Rosemary  wrote:

> real-address-in-sig@flur.bltigibbet (Rowland McDonnell) wrote:
> 
> > Rosemary  wrote:
> > 
> >> Rowland McDonnell wrote:
> >> > Rosemary  wrote: 
> 
> <snip>
> 
> > My dad was tested to have near-enough perfect vision by at least one
> > optician when he was in his 20s - well, aside from the colour
> > blindness, that is.  The optics were nigh on perfect, it's just that
> > he's got dodgy retinas.
> 
> "Just"? My short sight and astigmatism are easily fixed, with a bit of
> bent glass.

The fix is imperfect and awkward in all sorts of ways.

> You can't do that with colour blindness. 

But that doesn't get in the way of doing much.

[snip]

> > All I got was the straight spelling rule: `i before e except after c'
> > which, it was alleged, applied to all instances of ie and ei.  And
> > like I said, I spotted that the claim was nonsense at the time.
> 
> That's stupid teachers for you. Who tells kids a rule which will help
> them spell words, without giving them the second half of the rule?

I heard it from more than one teacher.  I think either they didn't know
themselves, or they assumed that I'd been told the second part and just
needed a reminder of the first part.

> > That was one of the many occasions on which I learnt not to pay too
> > much attention to the claims of alleged experts.  I've never been
> > inclined to pay much attention to alleged authority.
> > 
> >> Anyway, weird's simple. It's we as in... well, we, and ird as in
> >> jird, or third. 
> > 
> > No, it's write the word, notice I've got it wrong (again) and try to
> > remember that it's an exception next time *before* I type the keys or
> > scribble the letters.
> 
> :-) But it's not an exception. Weird, their, weir, heir - none of them
> have a plain ee sound in the middle, like receipt or priest, so they 
> don't follow the rule. 

Yes, but you see, I've had something over 35 years of looking at the
spelling of such words from the point of view of `does it follow i
before e except after c rule, or not?' - and what I was doing in the
above paragraph was telling you what process I use here&now for working
out the spelling.

Given that I've got that method to work pretty reliably, there's no
particular urge to update the spelling rulebook, y'know?

>Just telling someone "i before e except after c" 
> is like saying Richard Of York Grew Brassicas helps you remember the 
> colours of the rainbow.

At least with the partial mnemonic, you've got *some* correct info.

> BTW I really like typing "colours". It has a nice shape on the keyboard.

Yes, I can see that.  I need a new keyboard.  This one's worn out.

Rowland.

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Rowland McDonnell wrote:
> Rosemary wrote:
>> Rowland McDonnell wrote: 
>
> <snip>
> 
>> > My dad was tested to have near-enough perfect vision by at least
>> > one optician when he was in his 20s - well, aside from the colour
>> > blindness, that is.  The optics were nigh on perfect, it's just
>> > that he's got dodgy retinas.
>> 
>> "Just"? My short sight and astigmatism are easily fixed, with a bit
>> of bent glass.
> 
> The fix is imperfect and awkward in all sorts of ways.

Perhaps, but when I require perfect vision I can get it, if I use the 
right choice out of glasses, contact lenses, or holding something really 
really close to my face :-)
 
>> You can't do that with colour blindness. 
> 
> But that doesn't get in the way of doing much.

Maybe not, but it's still annoying that we haven't yet found a way of 
correcting a common visual problem like colour-blindness.
 
<snip>

> Yes, but you see, I've had something over 35 years of looking at the
> spelling of such words from the point of view of `does it follow i
> before e except after c rule, or not?' - and what I was doing in the
> above paragraph was telling you what process I use here&now for
> working out the spelling.
> 
> Given that I've got that method to work pretty reliably, there's no
> particular urge to update the spelling rulebook, y'know?

If it were me, I'd have thrown away i before e by now.
 
<snip>

Rosemary

Rosemary  wrote:

> Rowland McDonnell wrote:
> > Rosemary wrote:
> >> Rowland McDonnell wrote: 
> >
> > <snip>
> > 
> >> > My dad was tested to have near-enough perfect vision by at least
> >> > one optician when he was in his 20s - well, aside from the colour
> >> > blindness, that is.  The optics were nigh on perfect, it's just
> >> > that he's got dodgy retinas.
> >> 
> >> "Just"? My short sight and astigmatism are easily fixed, with a bit
> >> of bent glass.
> > 
> > The fix is imperfect and awkward in all sorts of ways.
> 
> Perhaps, but when I require perfect vision I can get it,

No, you don't get perfect vision - you get /improved/ vision.

> if I use the 
> right choice out of glasses, contact lenses, or holding something really
> really close to my face :-)

All that can do is partially correct yer eyes' optical defects.  There's
no way in creation that anyone can have *perfect* vision, no matter
what.

Partial correction of defects is the best that opticians can manage.
Pretty damned good eyesight is the best that anyone can have - naturally
or correct.

FWIW, some days my eyes don't like focussing (almost as if they're still
asleep, sort of thing).  Until my eyes get with it and start to change
focus for me, I suffer a blurry world at whatever distance my eyes have
decided to be not focussed on.

Other days, there's no trouble at all.

(and while my eyesight with both eyes is pretty good, the eyes one by
one are not - especially not the left one.  Bizzare that I can add the
blurry left eye picture to the visual input and get a massive
improvement in picture sharpness, but there you go.  I get the idea that
what I think of as `blurry' isn't really very blurry from the viewpoint
of people who need glasses, based on what I see on donning the specs of
others)

> >> You can't do that with colour blindness. 
> > 
> > But that doesn't get in the way of doing much.
> 
> Maybe not, but it's still annoying that we haven't yet found a way of
> correcting a common visual problem like colour-blindness.

My dad didn't find it annoying - and he did seem to find it annoying
when he started to need specs for close work.

> <snip>
> 
> > Yes, but you see, I've had something over 35 years of looking at the
> > spelling of such words from the point of view of `does it follow i
> > before e except after c rule, or not?' - and what I was doing in the
> > above paragraph was telling you what process I use here&now for
> > working out the spelling.
> > 
> > Given that I've got that method to work pretty reliably, there's no
> > particular urge to update the spelling rulebook, y'know?
> 
> If it were me, I'd have thrown away i before e by now.

Sod spelling reform.

Rowland.

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Rowland McDonnell wrote:
> Rosemary wrote:

<snip>

>> when I require perfect vision I can get it,
> 
> No, you don't get perfect vision - you get /improved/ vision.

Well, okay. I don't want to start another discussion about semantics. When 
I need to be able to see at least as well as those who have what opticians 
consider optimal functioning for the human eye, I can achieve that. Also, I 
have the option of seeing things super close if I should so desire. If I 
don't use correction I can focus on the pores and hairs on my nose. Not 
many people can do that.
 
>> if I use the 
>> right choice out of glasses, contact lenses, or holding something
>> really really close to my face :-)
> 
> All that can do is partially correct yer eyes' optical defects. 

There's an argument to be made for me having an optical enhancement. I am 
the human microscope - rarrrggghh!

<snip>

> FWIW, some days my eyes don't like focussing (almost as if they're
> still asleep, sort of thing).  Until my eyes get with it and start to
> change focus for me, I suffer a blurry world at whatever distance my
> eyes have decided to be not focussed on.

I get strange things like that when I have a migraine. I also get this 
weird effect where whatever it is I'm looing directly at disappears, and 
it's only at times like that when I think about how crappy human vision is 
anywhere other than the fovea.
 
<snip>

>> Maybe not, but it's still annoying that we haven't yet found a way of
>> correcting a common visual problem like colour-blindness.
> 
> My dad didn't find it annoying - and he did seem to find it annoying
> when he started to need specs for close work.

Annoying for people as a whole - it's obviously difficult to miss something 
you never had, though there are problems with the world being set up for 
people who can see all the colours people can normally see.

Still, my vision is easily corrected; a colour-blind person's is not.
 
<snip>

>> If it were me, I'd have thrown away i before e by now.
> 
> Sod spelling reform.

?

Rosemary

Rosemary  wrote:

> Rowland McDonnell wrote:
> > Rosemary wrote:
> 
> <snip>
> 
> >> when I require perfect vision I can get it,
> > 
> > No, you don't get perfect vision - you get /improved/ vision.
> 
> Well, okay. I don't want to start another discussion about semantics.

So you don't care to explore how you know what you know?  And you want
to ignore any communication problems completely, pretending that they
don't exist?

> When 
> I need to be able to see at least as well as those who have what opticians
> consider optimal functioning for the human eye, I can achieve that.

Uhuh.  Contact lenses are good enough to make your vision as good as it
ought to be - specs aren't.  It's the whole field of view thang.

> Also, I 
> have the option of seeing things super close if I should so desire. If I
> don't use correction I can focus on the pores and hairs on my nose. Not
> many people can do that.

Hmm!

I can't do that and the end of my nose is a lot further away from my
eyeballs than yours is.

> >> if I use the 
> >> right choice out of glasses, contact lenses, or holding something
> >> really really close to my face :-)
> > 
> > All that can do is partially correct yer eyes' optical defects. 
> 
> There's an argument to be made for me having an optical enhancement.

Erm, eh?  Do you mean your specs?

> I am 
> the human microscope - rarrrggghh!

Not quite as scary as Godzilla, but keep working on it.

> <snip>
> 
> > FWIW, some days my eyes don't like focussing (almost as if they're
> > still asleep, sort of thing).  Until my eyes get with it and start to
> > change focus for me, I suffer a blurry world at whatever distance my
> > eyes have decided to be not focussed on.
> 
> I get strange things like that when I have a migraine. I also get this
> weird effect where whatever it is I'm looing directly at disappears,

Sounds like your eyes aren't moving their point of vision, sort of
thing.  Stationary things vanish in sight, 'cos it's edges and movement
that your visual apparatus is set up to detect.

> and 
> it's only at times like that when I think about how crappy human vision is
> anywhere other than the fovea.

Human vision is staggeringly marvellous if you ask me.  The fact that we
can gather so much information so quickly from visual input is quite
wonderful.

It's not just the optics (the curved retina means you can get good focus
without chromatic aberration and so on with a simple single lens -
cunning, eh?), but also the detector and the data transmission and the
back end processing.  It's an astonishing piece of kit, it really is.

You can look at a scene, and inside fraction of a second you will have
identified all the major features and assessed their distance and
movement, and not long after you'll have done a full-on assessment of
their relationship to you taking into account everything inside your
head.

Machines can't do that.  They can barely identify a human face with
intensive training, let alone analyse a complex scene.  And none of them
have the ability to cope with partial information, noise, and varying
light levels as well as people can.

(the entertaining upside of the marvels of human vision is that it's so
good at spotting things and compensating for others that it can be
fooled into making you see things that aren't there - hence optical
illusions, all of which take advantage of visual system mechanisms and
optimizations that are hugely beneficial to human vision in the real
world, in the general case)

Machines can be trained to spot human faces with a good degree of
reliability - but they can't do it as reliably as a person can, and as
far as I know there aren't any cameras that can work over the dynamic
range that human eyes can handle - the range of light levels, that is.

Did you know that the human visual system can register in your mind a
packet of about (IIRC) a dozen photons, and the only reason for it
needing that many is that that's only just above the noise floor.

> <snip>
> 
> >> Maybe not, but it's still annoying that we haven't yet found a way of
> >> correcting a common visual problem like colour-blindness.
> > 
> > My dad didn't find it annoying - and he did seem to find it annoying
> > when he started to need specs for close work.
> 
> Annoying for people as a whole 

Is it?  I've not noticed.  My dad finds it something that's `just
something he's got to work round'.  I've not noticed him every being
annoyed by it, for all that he has to ask people about some things some
times.

>- it's obviously difficult to miss something 
> you never had, though there are problems with the world being set up for
> people who can see all the colours people can normally see.

I've asked my dad about that, and in his case, he only has trouble with
resistor (and capacitor) colour codes, apparently.  Everything else, he
can deal with - apparently.

> Still, my vision is easily corrected; a colour-blind person's is not.

My dad's line seems to be that the colour blindness doesn't need
correcting, but an inability to focus does.

> <snip>
> 
> >> If it were me, I'd have thrown away i before e by now.
> > 
> > Sod spelling reform.
> 
> ?

Isn't that what you were suggesting with throwing away i before e?

Rowland.

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Rowland McDonnell wrote:
> Rosemary wrote:
>> Rowland McDonnell wrote:
>> > Rosemary wrote:
>
>> >> when I require perfect vision I can get it,
>> > 
>> > No, you don't get perfect vision - you get /improved/ vision.
>> 
>> Well, okay. I don't want to start another discussion about semantics.
> 
> So you don't care to explore how you know what you know?  And you want
> to ignore any communication problems completely, pretending that they
> don't exist?

No, because we've had that discussion before.
 
>> When 
>> I need to be able to see at least as well as those who have what
>> opticians consider optimal functioning for the human eye, I can
>> achieve that. 
> 
> Uhuh.  Contact lenses are good enough to make your vision as good as
> it ought to be - specs aren't.  It's the whole field of view thang.

I wear contact lenses most of the time - 30 day continuous wear ones, so 
if I wake up in the middle of the night I don't have to scrabble around 
for a pair of glasses. Unfortunately, they don't correct for the 
astigmatism I have in my right eye, as Ciba don't do 30 day continuous 
wear toric lenses. Bausch and Lomb do, but when I tried them they felt 
like hot coals in my eyes.
 
<snip>
>> >> if I use the 
>> >> right choice out of glasses, contact lenses, or holding something
>> >> really really close to my face :-)
>> > 
>> > All that can do is partially correct yer eyes' optical defects. 
>> 
>> There's an argument to be made for me having an optical enhancement.
> 
> Erm, eh?  Do you mean your specs?

No, I mean my ability to focus a lot closer than the average person. Any 
old pair of normal eyes can see stuff at the other side of the room :-)

I'd still prefer not to have the myopia, though, even though it would 
mean giving up the ability to read really tiny text clearly (like the 
text that looks like lines on paper money). There's been quite a few 
occasions when someone's asked me to look at something close up for them, 
and in the days before magnifying glasses I might have occasionally come 
in useful like that. Or possibly not.

>> > FWIW, some days my eyes don't like focussing (almost as if they're
>> > still asleep, sort of thing).  Until my eyes get with it and start
>> > to change focus for me, I suffer a blurry world at whatever
>> > distance my eyes have decided to be not focussed on.
>> 
>> I get strange things like that when I have a migraine. I also get
>> this weird effect where whatever it is I'm looing directly at
>> disappears, 
> 
> Sounds like your eyes aren't moving their point of vision, sort of
> thing.  Stationary things vanish in sight, 'cos it's edges and
> movement that your visual apparatus is set up to detect.

Maybe. It feel like it's just the fovea that's out of commission
 
>> and 
>> it's only at times like that when I think about how crappy human
>> vision is anywhere other than the fovea.
> 
> Human vision is staggeringly marvellous if you ask me.  The fact that
> we can gather so much information so quickly from visual input is
> quite wonderful.

Nothing to do with the eyes, though. That's all the brain. Eyes are 
staggeringly crap.
 
> It's not just the optics (the curved retina means you can get good
> focus without chromatic aberration and so on with a simple single lens
> - cunning, eh?), but also the detector and the data transmission and
> the back end processing.  It's an astonishing piece of kit, it really
> is. 

It's okay, but if an engineer produced something with the same tolerances 
as a human eye he'd be out of a job. "So, how many eyes in a production 
run of your design will require corrective lenses to function properly?" 
"Erm - about half.""And how reliable are they?" "Well, they reliably stop 
working properly after a few years - close vision starts to deteriorate 
in childhood and continues to a point where it needs correction after 
about 45 years. By the time they've been in use for 75 years, most will 
have clouded lenses." "Okay, well how about the colour detection 
system?" "Oh, somewhere between 10% and 15% do't detect colour 
properly." "But you get full all-round vision, yes?" "Well, obviously, 
the information from anywhere other than the fovea is very approximate - 
I haven't put enough light sensors in anywhere else, as the brain can 
extrapolate." "But there's all around peripheral vision?" "Well, yes - 
except for the big blind spot - but don't worry, We can get the brain to 
extrapolate that bit." 
 
> You can look at a scene, and inside fraction of a second you will have
> identified all the major features and assessed their distance and
> movement, and not long after you'll have done a full-on assessment of
> their relationship to you taking into account everything inside your
> head.

Brain.
 
> Machines can't do that.  They can barely identify a human face with
> intensive training, let alone analyse a complex scene.  And none of
> them have the ability to cope with partial information, noise, and
> varying light levels as well as people can.
> 
> (the entertaining upside of the marvels of human vision is that it's
> so good at spotting things and compensating for others that it can be
> fooled into making you see things that aren't there - hence optical
> illusions, all of which take advantage of visual system mechanisms and
> optimizations that are hugely beneficial to human vision in the real
> world, in the general case)

Brain also.
 
<snip>

>> >> Maybe not, but it's still annoying that we haven't yet found a way
>> >> of correcting a common visual problem like colour-blindness.
>> > 
>> > My dad didn't find it annoying - and he did seem to find it
>> > annoying when he started to need specs for close work.
>> 
>> Annoying for people as a whole 
> 
> Is it?  I've not noticed.  My dad finds it something that's `just
> something he's got to work round'.  I've not noticed him every being
> annoyed by it, for all that he has to ask people about some things
> some times.

Yes - the human race has managed to learn to correct the two most common 
causes of poor vision - refractive errors and cataracts - but we can't 
deal with something as common as colour-blindness.
 
<snip> 

>> Still, my vision is easily corrected; a colour-blind person's is not.
> 
> My dad's line seems to be that the colour blindness doesn't need
> correcting, but an inability to focus does.

He's never known any different, though. 
 
>> <snip>
>> 
>> >> If it were me, I'd have thrown away i before e by now.
>> > 
>> > Sod spelling reform.
>> 
>> ?
> 
> Isn't that what you were suggesting with throwing away i before e?

No, I just think that it's a pretty useless guide to helping people learn 
to spell.

Rosemary

Rosemary  wrote:

> Rowland McDonnell wrote:
> > Rosemary wrote:
> >> Rowland McDonnell wrote:
> >> > Rosemary wrote:
> >
> >> >> when I require perfect vision I can get it,
> >> > 
> >> > No, you don't get perfect vision - you get /improved/ vision.
> >> 
> >> Well, okay. I don't want to start another discussion about semantics.
> > 
> > So you don't care to explore how you know what you know?  And you want
> > to ignore any communication problems completely, pretending that they
> > don't exist?
> 
> No, because we've had that discussion before.

I don't recall engaging in a discussion with you on the subject.

> >> When 
> >> I need to be able to see at least as well as those who have what
> >> opticians consider optimal functioning for the human eye, I can
> >> achieve that. 
> > 
> > Uhuh.  Contact lenses are good enough to make your vision as good as
> > it ought to be - specs aren't.  It's the whole field of view thang.
> 
> I wear contact lenses most of the time - 30 day continuous wear ones, so
> if I wake up in the middle of the night I don't have to scrabble around
> for a pair of glasses. Unfortunately, they don't correct for the 
> astigmatism I have in my right eye, as Ciba don't do 30 day continuous
> wear toric lenses.

Oh.  Toric?  What, `like a torus'?  Surely that's not what you need for
astigmatism?  Hmm.  Erm.

Wikipedia says this:

"In optics, a toric lens is a type of lens whose surface is a
combination of a sphere and a cylinder. One surface of the lens is
spherical, the other toroidal.[1][2] Such lenses are commonly used for
vision correction, in cases where there is astigmatism."

No diagram, though.  I'd like to see an optical analysis of how it's
supposed to work.

> Bausch and Lomb do, but when I tried them they felt 
> like hot coals in my eyes.

Uhuh.

> <snip>
> >> >> if I use the 
> >> >> right choice out of glasses, contact lenses, or holding something
> >> >> really really close to my face :-)
> >> > 
> >> > All that can do is partially correct yer eyes' optical defects. 
> >> 
> >> There's an argument to be made for me having an optical enhancement.
> > 
> > Erm, eh?  Do you mean your specs?
> 
> No, I mean my ability to focus a lot closer than the average person. Any
> old pair of normal eyes can see stuff at the other side of the room :-)

Yeeesss....  Which is a bit more useful if you ask me.

I can still do close-up focussing as well as I need to - just shove the
anglepoise closer to the workpiece to close up the pupil and peer away,
just like I did when I was 14.

> I'd still prefer not to have the myopia, though, even though it would
> mean giving up the ability to read really tiny text clearly (like the
> text that looks like lines on paper money).

I can read that even without very bright light.  And it always looks
like lines of text to me, not just lines.

> There's been quite a few 
> occasions when someone's asked me to look at something close up for them,
> and in the days before magnifying glasses I might have occasionally come
> in useful like that. 

Corrective lenses for human vision were noted in antiquity - 1st century
AD is one I've come across.

>Or possibly not.

Oh yes, but in those days, the poor long-range vision would have been a
bit more of a problem.

FWIW, there are populations in the Far East which have 80% or so short
sighted people.  For some reason, that was clearly no evolutionary
disadvantage - but I wonder why.

> >> > FWIW, some days my eyes don't like focussing (almost as if they're
> >> > still asleep, sort of thing).  Until my eyes get with it and start
> >> > to change focus for me, I suffer a blurry world at whatever
> >> > distance my eyes have decided to be not focussed on.
> >> 
> >> I get strange things like that when I have a migraine. I also get
> >> this weird effect where whatever it is I'm looing directly at
> >> disappears, 
> > 
> > Sounds like your eyes aren't moving their point of vision, sort of
> > thing.  Stationary things vanish in sight, 'cos it's edges and
> > movement that your visual apparatus is set up to detect.
> 
> Maybe. It feel like it's just the fovea that's out of commission

Doesn't work like that.  Could be the blind spot on the retina that's
receiving the image, and if it stays there without triggering a signal,
then your brain will wipe out the image it's got stored eventually.

There's an optical illusion-type thing you can do to make things to do
the `vanish because they're still on the retina' thing, but I can't
recall the setup.


> >> and 
> >> it's only at times like that when I think about how crappy human
> >> vision is anywhere other than the fovea.
> > 
> > Human vision is staggeringly marvellous if you ask me.  The fact that
> > we can gather so much information so quickly from visual input is
> > quite wonderful.
> 
> Nothing to do with the eyes, though. That's all the brain. Eyes are 
> staggeringly crap.

But the human visual system works marvellously well - the eyes are the
transducers, and they're wonderfully well optimized for the job.

For example, there's no need to have high res imaging all over the
retina, and so we've only got high res imaging in one little patch.  And
that's all we need.  There's you wingeing about how the retina's crap
outside the fovea, but why should it be high res anywhere else?  No need
at all.

This particular optimization reduces the data transmission needs and
reduces the processing needed to turn that data into a useful `view
inside your head'.

The image data is linked to memory and processing to create a wide-angle
high res understanding of what's around you.

Like I said, there are few (or maybe no) cameras with the dynamic range
of an eye.  What about that point?  Human eyes do a useful job in lower
light levels than any non-image-intensifying camera.  That sort of
camera can't cope with normal indoor light, let alone the outdoors - but
human eyes can.  Hell, the human eye can, with a bit of squinting,
actually resolve the sun - don't do it, you risk a burnt out retina, but
I have done it when younger.

The curved retina is a very neat trick - which has only just been
replicated by man-made machinery, if what I've read recently is true.
It gives very high quality imaging with a single lens - neat.

The human eye-brain system works well - it works very very well indeed.
And it works well because all the parts are optimized for their roles as
part of the visual system.

> > It's not just the optics (the curved retina means you can get good
> > focus without chromatic aberration and so on with a simple single lens
> > - cunning, eh?), but also the detector and the data transmission and
> > the back end processing.  It's an astonishing piece of kit, it really
> > is. 
> 
> It's okay, but if an engineer produced something with the same tolerances
> as a human eye he'd be out of a job.

No he wouldn't - not with the same production specs.

You're missing a point, too: the eye is part of the human visual system.
If it were designed, the engineer would design the *system as a whole* -
not `don't worry, we can get the brain to exptrapolate that bit', but
`Right, we've got a job to do, what's the best way to get it done, yes,
this approach seems to provide the best performance overall with
practical parts'.

> "So, how many eyes in a production 
> run of your design will require corrective lenses to function properly?"
> "Erm - about half."

Not so: most people can get by perfectly well without any visual
correction.

>"And how reliable are they?" "Well, they reliably stop 
> working properly after a few years - close vision starts to deteriorate
> in childhood and continues to a point where it needs correction after
> about 45 years.

No, `The human visual system produces useful stereo imaging with very
powerful and rapid back-end analysis in almost all cases until the host
is dead, even while visual acuity drops off after several decades in use
- how cool is that, eh?'.

And `While visual acuity does drop off with the age deterioration that
affects all other parts of the host organism, the eyes are optimized so
that it's close range vision that goes first in most people, leaving
them with the more generally useful long-range vision still working
well.  Don't you think it's amazingly cool that I've managed to deal
even with the inevitable march of aging so incredibly neatly?'

> By the time they've been in use for 75 years, most will 
> have clouded lenses." 

No, `by the time they've had 3/4 of a century of use, most will need
some maintenance - and with care in operation, this very long period
before maintenance is needed can be extended - how cool is that, eh?'

>"Okay, well how about the colour detection 
> system?" "Oh, somewhere between 10% and 15% do't detect colour 
> properly." "But you get full all-round vision, yes?" "Well, obviously,
> the information from anywhere other than the fovea is very approximate -
> I haven't put enough light sensors in anywhere else, as the brain can
> extrapolate."

No, `the information from anywhere by the fovea is low-resolution, but
that's ideally optimized for system operation given the use to which
they're going to be put - how cool is that, eh?'

>"But there's all around peripheral vision?" "Well, yes - 
> except for the big blind spot - but don't worry, We can get the brain to
> extrapolate that bit." 

No, `because the visual system works on filling in the gaps and
extrapolation, we don't need a full-area detector array, so we get to
use this very elegant data pickup - how cool is that, eh?'

And `The visual system is capable of producing nigh on perfect imaging
with only a single lens and single detector array per eye - how cool is
that, eh?'

And `Even when the eyes don't meet top spec, the human visual system is
still very powerful and useful to the unit which has it installed  - how
cool is that, eh?

`For example, with the highly sensitive motion detection and insanely
powerful image recognition facility with learning abilities that is
built into the visual system, you can spot and identify almost anything
that's trying to creep up on you and eat you well before they're within
danger range, thus giving you time to leg it up a tree.  Ook!

`And even if the eyes have deteriorated to the point where image
recognition isn't working at long range any more, you'll almost
certainly still get useful data from the motion detection, which will
probably be good enough to save your bacon'

And `The eyes self-maintaining - how cool is that, eh?'

And `They work automatically over a wider dynamic range than anything
else - how cool is that, eh?'

And `They're very mechanically robust and capable of taking massive
abuse over the course of decades - how cool is that, eh?'

And `They form part of a visual system with *these* characteristics,
made of nothing but highly mutually optimized parts, which puts them
streets ahead of anything else - how cool is that, eh?'

And `They can be made by totally unskilled labour whom we don't have to
pay and we don't even have to give them the slighest encouragement to
make these things - they'll just get on with it for free.  Could you
have even dreamt of that sort of manufacturing setup?'

That is, when the human visual system works at full spec, it's
staggeringly good.  When it's working off the peak, it's still pretty
good.  And you'll not find anything simpler or cheaper by way of visual
data capture devices than a biological eye.

If any engineer came up with a design for visual data capture and
analysis /system/ with the full specification of the human visual
/system/, and explained that manufacturing was to be by unskilled,
unpaid labour who would require no encouragement, I think people would
be impressed.

> > You can look at a scene, and inside fraction of a second you will have
> > identified all the major features and assessed their distance and
> > movement, and not long after you'll have done a full-on assessment of
> > their relationship to you taking into account everything inside your
> > head.
> 
> Brain.

Not only the brain.  The eyes and optical nerves form part of the visual
system too, you know.

> > Machines can't do that.  They can barely identify a human face with
> > intensive training, let alone analyse a complex scene.  And none of
> > them have the ability to cope with partial information, noise, and
> > varying light levels as well as people can.
> > 
> > (the entertaining upside of the marvels of human vision is that it's
> > so good at spotting things and compensating for others that it can be
> > fooled into making you see things that aren't there - hence optical
> > illusions, all of which take advantage of visual system mechanisms and
> > optimizations that are hugely beneficial to human vision in the real
> > world, in the general case)
> 
> Brain also.

Not only - it's the human visual system that does the job: all of it
working together.

> <snip>
> 
> >> >> Maybe not, but it's still annoying that we haven't yet found a way
> >> >> of correcting a common visual problem like colour-blindness.
> >> > 
> >> > My dad didn't find it annoying - and he did seem to find it
> >> > annoying when he started to need specs for close work.
> >> 
> >> Annoying for people as a whole 
> > 
> > Is it?  I've not noticed.  My dad finds it something that's `just
> > something he's got to work round'.  I've not noticed him every being
> > annoyed by it, for all that he has to ask people about some things
> > some times.
> 
> Yes - the human race has managed to learn to correct the two most common
> causes of poor vision - refractive errors and cataracts - but we can't
> deal with something as common as colour-blindness.

<puzzled>  Yes we can - we just live with it.

Anyway, colour blindness is a defect of the retina - of course it's
going to be a sod to deal with.

> <snip> 
> 
> >> Still, my vision is easily corrected; a colour-blind person's is not.
> > 
> > My dad's line seems to be that the colour blindness doesn't need
> > correcting, but an inability to focus does.
> 
> He's never known any different, though. 

<puzzled>  He knows that there are colours he cannot distinguish like
normal people can - although he *can* often spot the difference between
colours that he's allegedly not supposed to be able to.  He looks for
subtle differences in shading which he's learnt tell him what's what.

But the point is that my dad's colour blindness does not act as any kind
of disability - except that he has to ask for help when reading resistor
colour codes.  That's the only problem it caused him.

Do you get the point?  Colour blindness of the sort my dad has doesn't
stop you doing anything much - so it's a trivial disability.

> >> <snip>
> >> 
> >> >> If it were me, I'd have thrown away i before e by now.
> >> > 
> >> > Sod spelling reform.
> >> 
> >> ?
> > 
> > Isn't that what you were suggesting with throwing away i before e?
> 
> No, I just think that it's a pretty useless guide to helping people learn
> to spell.

Ah!  Yes.

Rowland.

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wrote in message 
news:3571ec93-85f8-4797-91aa-7e767d045479@p25g2000hsf.googlegroups.com...
x-no-archive: yes

On Aug 20, 12:21 pm, Rosemary  wrote:

> If an engineer produced something with the same tolerances
> as a human eye he'd be out of a job.

That's because they evolved through trial and error. Perhaps in a few
million years time humans will have eyes fit for the purpose, although
since we seem to be breeding for perceived beauty rather than
functionality I very much doubt it.


<snip>

If survival of the species still depended on good vision I would agree 
with you. But it doesn't - and I don't.

Rowland McDonnell wrote:
> Rosemary wrote:
>> Rowland McDonnell wrote:
>> > Rosemary wrote:
>> >> Rowland McDonnell wrote:
>> >> > Rosemary wrote:

<snip>

>> >> Well, okay. I don't want to start another discussion about
>> >> semantics. 
[...]
> I don't recall engaging in a discussion with you on the subject.

I do :-)

<snip>

>> >> >> if I use the 
>> >> >> right choice out of glasses, contact lenses, or holding
>> >> >> something really really close to my face :-)
>> >> > 
>> >> > All that can do is partially correct yer eyes' optical defects. 
>> >> 
>> >> There's an argument to be made for me having an optical
>> >> enhancement. 
>> > 
>> > Erm, eh?  Do you mean your specs?
>> 
>> No, I mean my ability to focus a lot closer than the average person.
>> Any old pair of normal eyes can see stuff at the other side of the
>> room :-) 
> 
> Yeeesss....  Which is a bit more useful if you ask me.

Always look on the bright side of life, they say. I think it's funny to 
annoy those people with good sight who take the piss by pointing out what 
_they_ can't see but I can.
 
<snip>

>> I'd still prefer not to have the myopia, though, even though it would
>> mean giving up the ability to read really tiny text clearly (like the
>> text that looks like lines on paper money).
> 
> I can read that even without very bright light.  And it always looks
> like lines of text to me, not just lines.

Do you mean the bit under the Queen's head? On the £5, it's lines of text 
in a kind of blocky design, on the £10 it's in little spirals, and  on the 
£20 it's in a squirly design around the word twenty and the number 20. I'm 
impressed if you can make out the individual letters clearly on those at 40 
and with no myopia. 
 
<snip>

>> >> I get strange things like that when I have a migraine. I also get
>> >> this weird effect where whatever it is I'm looing directly at
>> >> disappears, 
>> > 
>> > Sounds like your eyes aren't moving their point of vision, sort of
>> > thing.  Stationary things vanish in sight, 'cos it's edges and
>> > movement that your visual apparatus is set up to detect.
>> 
>> Maybe. It feel like it's just the fovea that's out of commission
> 
> Doesn't work like that.

I know, but that's what it feels like.

<snip>
 
>> >> it's only at times like that when I think about how crappy human
>> >> vision is anywhere other than the fovea.
>> > 
>> > Human vision is staggeringly marvellous if you ask me.  The fact
>> > that we can gather so much information so quickly from visual input
>> > is quite wonderful.
>> 
>> Nothing to do with the eyes, though. That's all the brain. Eyes are 
>> staggeringly crap.
> 
> But the human visual system works marvellously well - the eyes are the
> transducers, and they're wonderfully well optimized for the job.
> 
> For example, there's no need to have high res imaging all over the
> retina, and so we've only got high res imaging in one little patch. 
> And that's all we need.  There's you wingeing about how the retina's
> crap outside the fovea, but why should it be high res anywhere else? 
> No need at all.

Whingeing? I just hate bad design, especially considering all the trouble I 
have to go to to keep my teeth working properly. :-) I think eyes could be 
seriously improved. It's all compromises - we have these huge malformed 
heads to fit in immense brains, and look at all the problems it's caused. 
Eyes, nose, jaws, hearing - all compromised. Giving birth is difficult 
because of these oversized heads, combined with the bizarre-shaped pelvis 
that we need in order to be able to walk upright (which I suppose is also 
partly because of the huge head, it being easier to carrystuck on top of a 
vertical column than hanging off the end of a horizontal one.

<snip>

>> "So, how many eyes in a production 
>> run of your design will require corrective lenses to function
>> properly?" "Erm - about half."
> 
> Not so: most people can get by perfectly well without any visual
> correction.

Get by, perhaps, They don't have optimal vision, though. Hawks with bad 
eyesight die. People with bad eyesight survive - something to do with 
social systems and intelligence, I suppose. And Bad eyesight might be 
linked to humans' oversized brains anyway.
 
<snip>

> That is, when the human visual system works at full spec, it's
> staggeringly good.  When it's working off the peak, it's still pretty
> good.  

Try telling that to anyone in my family. I don't have a single relative I 
know of who doesn't have such compromised vision that they'd be incapable 
of seeing a berry on a bush 5 feet away, and completely useless at hunting 
anything faster than a cabbage.

<snip>

>> >> >> Maybe not, but it's still annoying that we haven't yet found a
>> >> >> way of correcting a common visual problem like
>> >> >> colour-blindness. 
>> >> > 
>> >> > My dad didn't find it annoying - and he did seem to find it
>> >> > annoying when he started to need specs for close work.
>> >> 
>> >> Annoying for people as a whole 
>> > 
>> > Is it?  I've not noticed.  My dad finds it something that's `just
>> > something he's got to work round'.  I've not noticed him every
>> > being annoyed by it, for all that he has to ask people about some
>> > things some times.
>> 
>> Yes - the human race has managed to learn to correct the two most
>> common causes of poor vision - refractive errors and cataracts - but
>> we can't deal with something as common as colour-blindness.
> 
> <puzzled>  Yes we can - we just live with it.

Doesn't the idea of just living with a problem that theoretically one day 
may be solved annoy you, as a concept? For most people, colour blindness 
can just cause occasional mild irritation (like it does for my uncle), 
that's true. But it just irks me a bit that something so common is 
untreatable.
 
> Anyway, colour blindness is a defect of the retina - of course it's
> going to be a sod to deal with.

Well, yes, obviously. But I just feel annoyed when there's any common 
physical or mental problem that can't be at least treated. It just makes me 
feel that as an intelligent species we're failing vast numbers of our 
members. I don't know why. Very common problems which we have no method of 
treating or curing offend my delicate sensibilities :-)

I suppose death could come under this category, being as common as it is, 
but without death we wouldn't exist anyway, so I can't get that peeved.
 
<snip> 

> But the point is that my dad's colour blindness does not act as any
> kind of disability - except that he has to ask for help when reading
> resistor colour codes.  That's the only problem it caused him.
> 
> Do you get the point?  Colour blindness of the sort my dad has doesn't
> stop you doing anything much - so it's a trivial disability.

Yes, I get your point. I do have a close relative with colour-blindness, so 
I know what it's about. I know that people have ways of coping with mild 
colour-blindness in a world that's designed for people with full colour 
vision. I know it's not a huge disability for most people. Most people 
would not bother getting it corrected if there were any risk with a 
procedure that could do it. But still, refractive errors can be corrected 
(even mild ones, which have very little effect on day-to-day functioning), 
whereas colour-blindness simply cannot. Do _you_ get the point?

People with a very mild refractive error often don't notice, and even if 
they do they sometimes think there'd be no point getting it fixed because 
the reduction in vision quality is small enough that it doesn't affect 
their day-to-day functioning. They don't know any different; their vision 
has always been like that. If and when they get their refractive error 
corrected, they may realise what they've been missing.
 
Rosemary

Evil_Nigel@hotmail.co.uk wrote:

> x-no-archive: yes
> 
> On Aug 20, 12:21 pm, Rosemary  wrote:
> 
>> If an engineer produced something with the same tolerances
>> as a human eye he'd be out of a job.
> 
> That's because they evolved through trial and error. Perhaps in a few
> million years time humans will have eyes fit for the purpose, although
> since we seem to be breeding for perceived beauty rather than
> functionality I very much doubt it.

I doubt it too, especially since people with bad short or long sight
don't really get hoicked out of the gene pool any more since there's no
real disadvantage any more (I know there's some parts of the world where
they still can't get glasses, but with any luck that problem will recede
a bit). Maybe the reason it's not gone already is because people are so
social and a role was usually found for people who had poor sight. I
wonder what the rates of short and long sight are in places where eye
tests and glasses aren't accessible. 
 
<snip>

> I believe everyone has a different perception of colours and I've been
> in some interesting discussions about what a particular hue should be
> called.

I'm firmly of the opinion that everyone has the same favourite colour, 
it's just that purple (my favourite colour) looks the same to me as red 
does to someone whose favourite colour is red. :-)

Rosemary

x-no-archive: yes

Evil_Nigel@hotmail.co.uk wrote:
> Rosemary wrote:
>
>> I'm firmly of the opinion that everyone has the same favourite
>> colour, it's just that purple (my favourite colour) looks the same to
>> me as red does to someone whose favourite colour is red. :-)
> 
> I think I know what red is - it's the colour of pillar boxes! And yet
> someone keeps sending me 'red flowered' plants which turn out to have
> orange flowers.

Ooh - secret admirer? :-)
 
> My digital camera seems to have difficulty faithfully reproducing
> purple/lilac/pink shades, but it is quite elderly now.

That's weird. I didn't know digital cameras did that - I suppose I just 
assumed that sooner or later the CCD or something would die and it'd stop 
working.

Rosemary

Rosemary  wrote:

> > Rosemary  wrote:
> > 
> >> If an engineer produced something with the same tolerances
> >> as a human eye he'd be out of a job.
> > 
> > That's because they evolved through trial and error. Perhaps in a few
> > million years time humans will have eyes fit for the purpose, although
> > since we seem to be breeding for perceived beauty rather than
> > functionality I very much doubt it.
> 
> I doubt it too, especially since people with bad short or long sight
> don't really get hoicked out of the gene pool any more since there's no
> real disadvantage any more (I know there's some parts of the world where
> they still can't get glasses, but with any luck that problem will recede
> a bit).

That's not got a lot to do with it.  There are populations in the Far
East where up to 80% of the people are short sighted to the extent that
they need correction.

The evolutionary fact of the matter is that short sight isn't much of a
problem for people in general  Human eyesight, even when `well of
optimal' is magnificently useful, it really is.

> Maybe the reason it's not gone already is because people are so
> social and a role was usually found for people who had poor sight.

Maybe people with short sight found their own roles.  Maybe it's the
case that having good long range vision isn't very useful for most
people.  Maybe good short range vision is a lot more important for most.

Maybe that's why short sightedness is so common - and long sightedness
rarer, 'cos it's more of a problem.

Maybe neither of us has a clue and we're just pissing in the wind.

> I
> wonder what the rates of short and long sight are in places where eye
> tests and glasses aren't accessible. 

It varies hugely with population - the population of Japan has a /much/
higher percentage of short sightedness than does Italy.

Italians started to use spectacles in about the 13th-14th century.

Using that data, there is an inverse relationship between `using specs'
and `bad eyesight in the population'.

(Is the mechanism: "if your face /isn't/ disfigured by specs, you can
get a shag, but not otherwise."?  <grin>)

On the other hand, one would hardly expect to see any variation due to
evolutionary effects over 700+ years with such a small factor.


> <snip>
> 
> > I believe everyone has a different perception of colours and I've been
> > in some interesting discussions about what a particular hue should be
> > called.
> 
> I'm firmly of the opinion that everyone has the same favourite colour,
> it's just that purple (my favourite colour) looks the same to me as red
> does to someone whose favourite colour is red. :-)

I'm firmly of the opinion that such speculation is terrifically
interesting, but that it's going to be very hard to gather any data to
test the thinking.

Rowland.

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Rosemary  wrote:

> > Rosemary  wrote:
> > 
> >> If an engineer produced something with the same tolerances
> >> as a human eye he'd be out of a job.
> > 
> > That's because they evolved through trial and error. Perhaps in a few
> > million years time humans will have eyes fit for the purpose,

Human eyes *are* fit for purpose - they've evolved to be so over the
hundred millions of years that eyes have been evolving on Earth.

I really cannot understand how anyone could suggest anything else: given
how evolution works, all highly evolved body parts are fit for purpose
pretty much by definition.

Nothing's perfect in all respects, of course - all evolved systems have
compromises about them.  And we cannot assess these compromises because
we've not got the long view of evolution and species that is required to
achieve that long view.

Or, to put it another way, any criticism of the results of evolution
cannot take into account the full facts and so is invalid.

[snip]

Rowland.

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Rosemary  wrote:

> Rowland McDonnell wrote:
> > Rosemary wrote:
> >> Rowland McDonnell wrote:
> >> > Rosemary wrote:
> >> >> Rowland McDonnell wrote:
> >> >> > Rosemary wrote:
[snip]
> >> >> >> if I use the 
> >> >> >> right choice out of glasses, contact lenses, or holding
> >> >> >> something really really close to my face :-)
> >> >> > 
> >> >> > All that can do is partially correct yer eyes' optical defects.
> >> >> 
> >> >> There's an argument to be made for me having an optical
> >> >> enhancement. 
> >> > 
> >> > Erm, eh?  Do you mean your specs?
> >> 
> >> No, I mean my ability to focus a lot closer than the average person.
> >> Any old pair of normal eyes can see stuff at the other side of the
> >> room :-) 
> > 
> > Yeeesss....  Which is a bit more useful if you ask me.
> 
> Always look on the bright side of life, they say. I think it's funny to
> annoy those people with good sight who take the piss by pointing out what
> _they_ can't see but I can.

I've had people try that one on me in the past.  Bright light has always
been my saviour: turn on the 150W anglepoise, shove it right up against
the workpiece, and I always found I could see anything that these
supposedly `super sighted due to short sightedness' people could see.

But that was when I was in my teens and early 20s.  My eyes are
definitely not as good as they used to be.

> <snip>
> 
> >> I'd still prefer not to have the myopia, though, even though it would
> >> mean giving up the ability to read really tiny text clearly (like the
> >> text that looks like lines on paper money).
> > 
> > I can read that even without very bright light.  And it always looks
> > like lines of text to me, not just lines.
> 
> Do you mean the bit under the Queen's head? On the £5, it's lines of text
> in a kind of blocky design, on the £10 it's in little spirals, and  on the
> £20 it's in a squirly design around the word twenty and the number 20. I'm
> impressed if you can make out the individual letters clearly on those at 40
> and with no myopia. 

Ah.  That text.  No, I can't read that without assistance (at least, not
today).  I've just tried, with max bright light.

However, I reckon I could have done 20 years ago.  My near point has
moved out a long way, or so I've just discovered.

I am aware that at the moment, my eyes are not being very co-operative
and feel a bit `stiff'.  I suspect that I'll have more flexible
focussing later on or tomorrow.   The near point I've just run in to is
a lot further out that I was expecting, put it like that.

> <snip>
> 
> >> >> I get strange things like that when I have a migraine. I also get
> >> >> this weird effect where whatever it is I'm looing directly at
> >> >> disappears, 
> >> > 
> >> > Sounds like your eyes aren't moving their point of vision, sort of
> >> > thing.  Stationary things vanish in sight, 'cos it's edges and
> >> > movement that your visual apparatus is set up to detect.
> >> 
> >> Maybe. It feel like it's just the fovea that's out of commission
> > 
> > Doesn't work like that.
> 
> I know, but that's what it feels like.

Not to me, it doesn't.  It feels like `blanking out the non-moving parts
of the scene' to me.

> <snip>
>  
> >> >> it's only at times like that when I think about how crappy human
> >> >> vision is anywhere other than the fovea.
> >> > 
> >> > Human vision is staggeringly marvellous if you ask me.  The fact
> >> > that we can gather so much information so quickly from visual input
> >> > is quite wonderful.
> >> 
> >> Nothing to do with the eyes, though. That's all the brain. Eyes are
> >> staggeringly crap.
> > 
> > But the human visual system works marvellously well - the eyes are the
> > transducers, and they're wonderfully well optimized for the job.
> > 
> > For example, there's no need to have high res imaging all over the
> > retina, and so we've only got high res imaging in one little patch.
> > And that's all we need.  There's you wingeing about how the retina's
> > crap outside the fovea, but why should it be high res anywhere else?
> > No need at all.
> 
> Whingeing? I just hate bad design,

Thinking that eyes are badly designed is a mistake.  They're marvellous
bits of kit which are staggeringly well optimized for the job.  The fact
that they don't let everyone read newsprint at arms's length isn't a
serious defect - not when you consider what they can do and how they fit
into the grand scheme of evolution of life on Earth.

Don't think of eyes as being the organs you personally use for seeing -
look at them as a range of organs developed as part of the evolutionary
process to improve the evolutionary fitness of the species (plural)
which use them.

And they're *blinding* at that job, they really are.

(you may shoot me now)

> especially considering all the trouble I 
> have to go to to keep my teeth working properly. :-)

Teeth are pretty good too - plenty of people have plenty of okay teeth
even in their 60s these days, which is excellent for gadget that evolved
in an organism which usually didn't live to the age of 40.

> I think eyes could be 
> seriously improved. 

The only `improvement' we need is more consistency in manufacturing -
but given the way evolution works, I'm not sure that'd necessarily be
better for the species, although it would definitely be better for the
individual.

>It's all compromises

Quite - all of it must always be the intersection of more compromises
than *anyone can possibly even imagine*, so don't try to second-guess
evolution.

> - we have these huge malformed 
> heads

Except that they're not malformed, are they?  And they're only big when
compared to some other animals.

> to fit in immense brains, and look at all the problems it's caused. 
> Eyes, nose, jaws, hearing - all compromised.

<puzzled>  Well, of course - everything in evolution has to be a
compromise.

> Giving birth is difficult 
> because of these oversized heads,

<sunny grin>  Not a problem for *ME*, not personally.

> combined with the bizarre-shaped pelvis 
> that we need in order to be able to walk upright (which I suppose is also
> partly because of the huge head,

What's bizarre about it?  The human pelvis works superbly well - we can
walk upright much better than any other bipedal animal I can think of,
and there is no Earthly animal that can travel long distances overland
as rapidly as a human being.

Even women, who do have odd pelvises, can travel much longer distances
overland much faster than any other species.

> it being easier to carrystuck on top of a 
> vertical column than hanging off the end of a horizontal one.

Quite - ISTR that we have hips based on the `bird' design rather than
the `lizard' design.  And we're better at walking than either lizards or
birds if you ask me.

> <snip>
> 
> >> "So, how many eyes in a production 
> >> run of your design will require corrective lenses to function
> >> properly?" "Erm - about half."
> > 
> > Not so: most people can get by perfectly well without any visual
> > correction.
> 
> Get by, perhaps, They don't have optimal vision, though.

So?  `Getting by' is all you need.

> Hawks with bad 
> eyesight die.

Hawks without the ability to spot prey while hunting starve to death.
It's not quite the same thing.  A long-sighted hawk probably doesn't
have any serious problems.

> People with bad eyesight survive - something to do with 
> social systems and intelligence, I suppose. And Bad eyesight might be
> linked to humans' oversized brains anyway.

Why?

Why assume that other species do not suffer from bad eyesight?
Certainly all insects have awful eyesight compared to mammalian vision
working well.  Think about it - what's `good eyesight'?

Your uncorrected eyesight is incomparably superior to that of a flatworm
with one photodetector per eye and a scanning system to build up
whatever passes for image in whatever passes for a flatworm's brain, for
example.

> <snip>
> 
> > That is, when the human visual system works at full spec, it's
> > staggeringly good.  When it's working off the peak, it's still pretty
> > good.  
> 
> Try telling that to anyone in my family. 

Rosemary, I don't know if you've noticed, but, erm, in telling you, I
*did* just try telling that to someone in your family.

>I don't have a single relative I 
> know of who doesn't have such compromised vision that they'd be incapable
> of seeing a berry on a bush 5 feet away,

That's unusually bad vision, that is, innit?  And in any case, so what?

> and completely useless at hunting 
> anything faster than a cabbage.

So?  Have you looked in the mirror lately?  Were you considering
yourself as a possible hunter of anything swift and in need of chasing?
Eyesight aside?

I've never had much time for the old `hunter gatherer' assumptions about
past human history and evolution in any case.  The models have always
struck me as far too trite, simplistic, and obvious - not to mention
`with absolutely no tested basis in measurement or modelling'.

People work in groups.  Someone with short sight can wield the shovel to
dig the pit to catch the mammoth.  Someone with long sight can go out
and see where the mammoths are from a long way away.

Someone with short sight can sit at home and look after the kids,
prepare the food, do the housework (which was substantial back in the
(say) English Iron Age roundhouse and farming era - and never mind back
in the days of even lower technological development).  And someone with
long sight can keep watch to make sure no bad people are approaching.

Even if you're completely blind, you've still got a brain and a memory -
someone's got to learn the stories and the songs and the laws and the
contracts and so on.  Who better than a blind person, who's got bugger
all else to do?

So visual defects in individuals need not be any disadvantage /at all/
to the community - be they minor defects such as the refractive errors
you've got, or major ones like only having light detection, not imaging,
from your eyes.

> <snip>
> 
> >> >> >> Maybe not, but it's still annoying that we haven't yet found a
> >> >> >> way of correcting a common visual problem like
> >> >> >> colour-blindness. 
> >> >> > 
> >> >> > My dad didn't find it annoying - and he did seem to find it
> >> >> > annoying when he started to need specs for close work.
> >> >> 
> >> >> Annoying for people as a whole 
> >> > 
> >> > Is it?  I've not noticed.  My dad finds it something that's `just
> >> > something he's got to work round'.  I've not noticed him every
> >> > being annoyed by it, for all that he has to ask people about some
> >> > things some times.
> >> 
> >> Yes - the human race has managed to learn to correct the two most
> >> common causes of poor vision - refractive errors and cataracts - but
> >> we can't deal with something as common as colour-blindness.
> > 
> > <puzzled>  Yes we can - we just live with it.
> 
> Doesn't the idea of just living with a problem that theoretically one day
> may be solved annoy you, as a concept?

<shrug>  Ageing and death are to my mind a much bigger personal problem
than anything to do with eyesight.

So's the fact that due to a failure over my lifetime to keep up the
plant breeding projects, the world now relies on cereal crops that are
losing their bred-in resistance to disease because the diseases have
evolved but people didn't want to spend the money on plant breeding to
keep up with Mother Nature - who is now going to bite us hard.

> For most people, colour blindness 
> can just cause occasional mild irritation (like it does for my uncle),
> that's true. But it just irks me a bit that something so common is 
> untreatable.

I'm more annoyed that `they' are making no attempt to treat (for
example) TB in either cows or badgers.

I'm more annoyed that UK government agricultural policy is to cull
animals that show any signs of resistance to diseases like TB or foot
and mouth.

> > Anyway, colour blindness is a defect of the retina - of course it's
> > going to be a sod to deal with.
> 
> Well, yes, obviously. But I just feel annoyed when there's any common
> physical or mental problem that can't be at least treated.

<shrug>  There aren't any mental problems that can be treated well.  I
get annoyed at all the people who have had their humanity stolen from
them by evil psychotropic drugs handed out by shrinks, whose main idea
is to use a chemical cosh on `those who will not conform' to keep them
prisoners inside their own heads.

Medicine is pretty crap at a lot of things - it's good at `helping the
body run things the way it wants to', but when the body has some sort of
build-in defect, things get trickier.

One of the big problems is the poor decisions made by the doctors.
Another of the big problems is the poor treatments available to them.

> It just makes me 
> feel that as an intelligent species we're failing vast numbers of our
> members. I don't know why. Very common problems which we have no method of
> treating or curing offend my delicate sensibilities :-)
> 
> I suppose death could come under this category, being as common as it is,
> but without death we wouldn't exist anyway, so I can't get that peeved.

I can.  Without the ability to stop aging and so `death by wearing out',
the human race has no hugely pressing need to leave the planet.

Once aging has been stopped, the human race would *HAVE* to spread out -
and also it would have to start forcing evolution.

(Why?  Because unless we did that, we'd infect the entire universe very
quickly and run out of space just like we would on this one planet.  We
have to evolve into gods.  See fiction by Arthur C. Clarke for further
details.)


> <snip> 
> 
> > But the point is that my dad's colour blindness does not act as any
> > kind of disability - except that he has to ask for help when reading
> > resistor colour codes.  That's the only problem it caused him.
> > 
> > Do you get the point?  Colour blindness of the sort my dad has doesn't
> > stop you doing anything much - so it's a trivial disability.
> 
> Yes, I get your point. I do have a close relative with colour-blindness, so
> I know what it's about. I know that people have ways of coping with mild
> colour-blindness in a world that's designed for people with full colour
> vision.

The world isn't designed - it just happened.  People sometimes use
colour as an indicator.  Most of the time, those with colour blindness
have not much trouble with that kind of thing.  That's about the only
time you need to think about it, when there are colour indicators - and
if you think about (for example) traffic lights, you have
colour+positional cues, so the fact that you might not be able to tell
red from green (or even up from down in extreme cases) doesn't matter:
if two lights are on at the same time, you *KNOW* it's `red/amber: start
stopping now'.

> I know it's not a huge disability for most people. Most people 
> would not bother getting it corrected if there were any risk with a 
> procedure that could do it. But still, refractive errors can be corrected
> (even mild ones, which have very little effect on day-to-day functioning),
> whereas colour-blindness simply cannot. Do _you_ get the point?

Well, yeah - but so what?

> People with a very mild refractive error often don't notice, and even if
> they do they sometimes think there'd be no point getting it fixed because
> the reduction in vision quality is small enough that it doesn't affect
> their day-to-day functioning. They don't know any different; their vision
> has always been like that. If and when they get their refractive error
> corrected, they may realise what they've been missing.

Most people miss out on the sensory experiences that they could have if
only they exposed themselves to the right things in the right way.

Look, here on Merseyside, I see advertising for a lot of public `music'
events put on by Liverpool council.

More this year, what with this European City of Constructions Grants to
Friends of the Planning Committee, 2008 business (they say it's European
City of Culture, but I say if it's about culture why have the destroyed
a city centre park to build stuff designed to make money, wiped out
historical buildings to replace them with much more lucrative buildings,
and spent a lot of money on improving roads so the people who want to
make money in these new buildings can get to and from them easily.

That's what `European City of Culture' is all about - wiping out culture
so that people can put up ugly buildings to make money.

Anyway, that rant's over.

Point is, we have all these `music' events.  I read the flyer for one
last year, IIRC.  All the events were listed - many days, many venues,
scores of `musical' performances.  Something for everyone, boasted the
flyer, produced by Liverpool City Council.

They were lying.  All the acts were contemporary pop acts.  All of them.

Absolutely nothing by *ANY* of the Bachs.  No Monteverdi.  No Martin
Carthy.  Not even any Motorhead.

Or, to put it another way, no music I'd be interested in; no music
anyone with any taste would like, as far as I'm concerned.

So you get all these cabbages, going to these concerts, thinking that
they've got a good idea what music's all about.

Until you've heard Monteverdi's vespers of 1610 sung live in a church
*AND* Motorhead at the Hammersmith Odeon (although not in the same
week)[1], you have no idea what music's about.

And that's just for starters.  There's an awful lot of other types of
music out there and you've got to listen to it if you want a clue.

Rowland.

[1]  Yes, you need both.  No get out clause, aside from `Okay, the
Hammersmith Apollo these days'.  And not just those two.  Lots and lots
of other stuff.   What about folk music?  All of it, from everywhere.

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Rosemary  wrote:

> Evil_Nigel@hotmail.co.uk wrote:
[snip]

> > My digital camera seems to have difficulty faithfully reproducing
> > purple/lilac/pink shades, but it is quite elderly now.
> 
> That's weird. I didn't know digital cameras did that - I suppose I just
> assumed that sooner or later the CCD or something would die and it'd stop
> working.

The thing to think about is that you need three detectors with a
specific spectral response - one for red, one for green, and one for
blue.

This chappie did colour photography using black and white film and
colour filters:

<http://www.loc.gov/exhibits/empire/>

(you'll see that `blue' is not quite the third colour he used, is it?)

Conventional modern (well, obsolescent) colour photographic film works
pretty much the same way, except that the colour filters are built into
the emulsion on the scale of the photographic grain.

But: many colour photography `triple CCD arrays' have a spectral
response that is totally pants from the point of view of capturing a
colour image that looks the way a human eye would view the scene.

A lot can be done by colour calibrating each CCD, balancing all three
against each other and so on, but that calibration must be done.  And
calibration can drift - either because the settings' moving, or because
the thing that the calibration applies to is drifting in response.

Blue detectors seem to be very bad for some reason.  And adjusting the
calibration for different light sources needs doing as well.

Incandescent electrical lighting typically has not a lot of blue light
at all - so indoor pictures taken with cheap digital cameras tend to a
yellow cast.  And modern `energy efficient' fluorescent lighting has a
discontinuous spectrum, different in the case of each lamp depending on
the mix of phosphors (generic name for `chemicals that emit light when
you smack 'em with something or other, electrons or photons usually').

So while it's possible to pre-calibrate for incandescent lighting
(making assumptions about filament temperature - one assumption for
`normal', another for `halogen', and so on), it's not really practical
to do the same for modern indoor lighting so modern indoor photography
with `normal ambient light' is sure to come out with poor colour
rendition.

An entertaining[1] problem that some people have these days is that
their colour vision is screwed up such that with some `compact
fluourescent' light sources, they think it's still dark when everyone
else thinks the lights are on.  In some cases, the spectral bands
emitted by these fancy new lamps are such that *some* people just can't
see the light at all.

The bloke I heard from noticed this problem in, IIRC, a Travelodge - he
just couldn't see to walk down the hallway, apparently.

The government and `green' lobby tell us are absolutely better without
any doubt and we must all use them for everything.  Yeah, right.

Rowland.

[1]  Well, it's entertaining if you just hear about it rather than
suffer from it, y'know?

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Rowland McDonnell wrote:

<snip all>

Basically, you are of the opinion that evolution works at a group level.

You're nuts.


Signed,

Rosemary

Rosemary  wrote:

> Rowland McDonnell wrote:
> 
> <snip all>
> 
> Basically, you are of the opinion that evolution works at a group level.

<puzzled>  What does that mean?

> You're nuts.

Well, yes.

Rowland.

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Rosemary wrote:

> 
> Basically, you are of the opinion that evolution works at a group level.
> 

We're top of the food chain and evolution is only trying to advance us 
in miniscule steps. It seems to me that technology is in pole position 
to take over.

In the past we've relied on technology to do a patch-up - spectacles and 
contact lenses, hearing aids, pacemakers. But we're now starting to wire 
up devices directly to the human nervous system.

Perhaps one day technologists will be able to build us replacement eyes 
that are fit for the purpose, supplying decent quality signals from 
short and long range objects to the optic nerve, and either lasting as 
long as the human operator or easily replaceable.

Evil Nigel

"nigel"  wrote in message 
news:g8v5lm$mcs$1@aioe.org...
> x-no-archive: yes
>
> Rosemary wrote:
>
>>
>> Basically, you are of the opinion that evolution works at a group 
>> level.
>>
>
> We're top of the food chain and evolution is only trying to advance us 
> in miniscule steps. It seems to me that technology is in pole position 
> to take over.
>
> In the past we've relied on technology to do a patch-up - spectacles 
> and contact lenses, hearing aids, pacemakers. But we're now starting 
> to wire up devices directly to the human nervous system.
>
> Perhaps one day technologists will be able to build us replacement 
> eyes that are fit for the purpose, supplying decent quality signals 
> from short and long range objects to the optic nerve, and either 
> lasting as long as the human operator or easily replaceable.
>
> Evil Nigel
>

We are Borg. You will be assimilated. Resistance is futile.

wrote in message 
news:b57da139-3696-4550-9c7f-f32c3992d20c@a1g2000hsb.googlegroups.com...
x-no-archive: yes

On Aug 25, 9:57 pm, "CJ Dunnaway" 
wrote:
> "nigel"  wrote in message
>
> > Perhaps one day technologists will be able to build us replacement
> > eyes that are fit for the purpose, supplying decent quality signals
> > from short and long range objects to the optic nerve, and either
> > lasting as long as the human operator or easily replaceable.
>
> > Evil Nigel
>
> We are Borg. You will be assimilated. Resistance is futile.

In my tabloid du jour there's a story of a one-year-old girl being
diagnosed with retinoblasta from a photograph e-mailed to a friend on
the other side of the world. In the photo, there is a whiteish shadow
to be seen.

Wouldn't it be great if the doomed, diseased eye could be replaced by
a biomechanical equivalent so the girl could grow up with normal
binocular vision.
(Even better if they could grow a replacement eye, but I don't see
that happening in the near future.)

(The girl is topless in the photograph - presumably that's acceptable
because no Boots jobsworths are required to report it to the police as
child pornography.)

Evil Nigel
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I was just making a joke. Yes, technology is wonderful. There are also 
cochlear implants to help people hear.

But I'm not sure the technology will be ready before natural 
replacements can be developed. I've been seeing numerous articles on 
advancements made through stem cell research. The last involved 
producing an unlimited supply of red blood cells. It seems new 
discoveries are being made on a daily basis now, and it won't be long 
before they can grow replacement body parts for people.

It won't happen next week, but it could happen in my lifetime (which is 
quite soon I think). I'm also intrigued by nanotechnology (another Borg 
sci-fi fantasy).

CJ

wrote in message 
news:6a8cb65f-319c-46a3-bf5f-ce9a00c1e2ac@m73g2000hsh.googlegroups.com...

<snip>

Prince Charles thinks nanotechnology could turn us all to grey mush.

Evil Nigel
~~~~~~~~~~~~~~~~~~~~~~~~
Really? I read he was afraid of genetically modified crops - I didn't 
know about the nanotech phobia. Not a scientifically inclined fellow, is 
he?

CJ

CJ Dunnaway wrote:
>  wrote in message 
> news:6a8cb65f-319c-46a3-bf5f-ce9a00c1e2ac@m73g2000hsh.googlegroups.com...
> 
> <snip>
> 
> Prince Charles thinks nanotechnology could turn us all to grey mush.
> 
> Evil Nigel


I thought it was only eating too many pot noodles that did that ;)


-- 
I'm F.I.N.E
*F*ucked UP *I*nsecure,*N*eurotic and *E*motional
Just FINE thanks :)
How are you?

CJ Dunnaway  wrote:

>  wrote:
> 
> <snip>
> 
> Prince Charles thinks nanotechnology could turn us all to grey mush.
> 
> Evil Nigel
> ~~~~~~~~~~~~~~~~~~~~~~~~
> Really? I read he was afraid of genetically modified crops

He's not.

> - I didn't 
> know about the nanotech phobia.

It's all lies.

> Not a scientifically inclined fellow, is 
> he?

Very much so.  But he's not very bright, and not very intellectually
inclined.  But he's got a good emotional understanding of the vital need
- the urgent need - to get this damned ecosystem of ours running
balanced again, instead of the `let's trash the place' economic system
that the USA (and others who make money now from ecological destruction)
is wanting the whole world to adopt.

The thing about Prince Charles is that he does *try* to understand and
he does get advice from the world's leading experts (one of the things
about royalty is that they can get that sort of thing).  You must bear
in mind two other things:

1) Every time I've listen to what Prince Charles himself had to say on a
particular subject of concern to him, it has struck me as fair,
balanced, reasonable, and very very sensible.

2) Every time I've met reports in `the media' about what Prince Charles
has said on such subjects, they have made him out to be a raving
fruitcake, using selective quotations and conventional journalistic
`just plain lying' to discredit his ideas by making him seem like a
complete and utter loon.

It's galling for *ME* to hear these `expert commentators' suggesting
that Charlie boy should get his facts straight and not go around
spreading distorted views of the facts with the intention of dissing
`whatever'.

- well, the people complaining about Charlie Boy in that line are all -
all of them! - spreading lies and distortions about what he's actually
said himself.  They are all of them guilty of what they accuse him of!
And they won't report what he said in a straight fashion!  They don't
try to understand what he's saying, they don't try to inform us - no,
Charlie Boy spouts off on some subject, and the press just attack him.

I think it's despicable, and I speak as a long-term anarchist.

Evil Nigel is joining in with this deliberately dishonest character
assassination.  I don't know why he enjoys doing this sort of thing.

Rowland.

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CJ Dunnaway  wrote:

>  wrote:
> 
> "CJ Dunnaway"  wrote:
> > "nigel"  wrote in message
> >
> > > Perhaps one day technologists will be able to build us replacement
> > > eyes that are fit for the purpose, supplying decent quality signals
> > > from short and long range objects to the optic nerve, and either
> > > lasting as long as the human operator or easily replaceable.

So human eyes are not fit for purpose, eh?

So how come that for all that we're outmassed by bacteria and
outnumbered by viruses, us human beings have climbed to the top of the
evolutionary tree on this 'ere ball of mud?

If my eyes were not fit for purpose, I would be unable to read your
words, or type a reply.  I would be unable to go shopping, or do any of
the other things I do that rely on my eyes.

This world has over 6 billion pairs of human eyes on it - and almost all
of their owners reckon that they've got something that does the job
okay.

> > We are Borg. You will be assimilated. Resistance is futile.
> 
> In my tabloid du jour there's a story of a one-year-old girl being
> diagnosed with retinoblasta from a photograph e-mailed to a friend on
> the other side of the world. In the photo, there is a whiteish shadow
> to be seen.
> 
> Wouldn't it be great if the doomed, diseased eye could be replaced by
> a biomechanical equivalent

Nope - 'cos that's not the way to go.  Bioelectronic, more like.

(We don't want a world looking like it was designed by Hans Giger,
anyway)

> so the girl could grow up with normal
> binocular vision.

Plenty of people have had electronic retinal implants to permit some
low-res vision from an eye incapable of anything but light detection.

They're getting better every year, very quickly.

> (Even better if they could grow a replacement eye, but I don't see
> that happening in the near future.)

Hmm?  I predict that `they' will be implanting lab-grown replacement eye
parts into eyes within 30 years.  I predict that the animal experiments
in that line will be taking place inside 10 years.

(if, that is, they've not already started).

You can expect to see old fogies growing new teeth rather sooner than
that.

> (The girl is topless in the photograph - presumably that's acceptable
> because no Boots jobsworths are required to report it to the police as
> child pornography.)
> 
> Evil Nigel
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> I was just making a joke. Yes, technology is wonderful. There are also
> cochlear implants to help people hear.
> 
> But I'm not sure the technology will be ready before natural 
> replacements can be developed.

Technology is everything that people do - everything.  Fire and stone
tools were the original high tech.

Electronic eye implants are in use now.  Work progresses on growing
spare body parts in the lab.  They can already do skin and some other
bits.  I think they're working on liver and suchlike.

These `natural' replacement parts are all a product of technology, for
all that they're squishy and not shiny stainless steel.

> I've been seeing numerous articles on 
> advancements made through stem cell research. The last involved 
> producing an unlimited supply of red blood cells. It seems new 
> discoveries are being made on a daily basis now, and it won't be long
> before they can grow replacement body parts for people.

It's old hat - old news.  Been done in the past.  In use now.

> It won't happen next week,

I guarantee that it will - as it happened last week.  It's being done
right now.  It's old hat.

> but it could happen in my lifetime (which is 
> quite soon I think). I'm also intrigued by nanotechnology (another Borg
> sci-fi fantasy).

It's here, now, in use in modern medicine providing treatment to those
who need it and can afford to pay.

Rowland.

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