Jim Henderson wrote:
> On Fri, 02 May 2008 21:10:47 +0200, andrel wrote:
> 
>>> (She's got ocular albinism, which means the rods and cones aren't fully
>>> developed, she lacks pigment in her iris, and the wiring to her brain
>>> is different than everyone else's -
>> I always found it fascinating how two seemingly unrelated things as how
>> the eyes connect to the left and right brain and pigmentation defects go
>> hand in hand. But that is as a scientist with an interest in
>> development. For the person involved it is probably slightly less
>> fascinating.
> 
> Oh, we both have found it very fascinating - her ophthalmologist took 
> pictures of her eyes - most people you get a bright center (from the 
> reflection off the retina), but for those with this condition, it's not 
> uncommon for the iris to "leak" light and for the photo to show a "spoke" 
> pattern outside the pupil area.
I think that also the white of the eye may transmit more.
[..]

> 
>>> - though for many this is a problem, my wife actually has managed to
>>> harness this somehow and as a result reads very fast.  But she wonders
>>> how other people actually see words on the page because she knows she's
>>> not reading the text linearly.
>> Less serious a problem, but I always wondered how the world would look
>> if it was out of focus. Whatever trick I used I was never able to not
>> focus. Well, time solved this one. Now to find out how the world looks
>> if you have a dominant eye. Possibly like walking with one eye closed,
>> but I guess it may be subtly different.
> 
> Well, the thing is, even when using just one eye, if your brain has had 
> practice at determining how far away stuff is, even with one eye you 
> adjust and still have depth perception.  I asked my wife about this (my 
> dad also had vision problems and I never understood the lack of depth 
> perception) - she explained it as a calculation problem - she can tell 
> how large something is compared to the surroundings, and if it's 
> something she knows how large it is relative to, say, her hand, that 
> helps - 
I'd imagine that all normal depth cues (you know, the ones we use when 
composing a good POV scene) should be available to her, some less 
because of the other visual problems.
> but her brain doesn't have enough practice at calculating the 
> distance of an object moving based on those two reference points, and as 
> a result, she has very poor eye-hand coordination when it comes to 
> catching something thrown in her direction, because in order to figure 
> out how far away something is, she actually has to think about it, while 
> those who don't have the problem don't have to think about it.  According 
> to her doctor, it comes back to things not being hooked up correctly 
> between the optics and the brain.

Makes sense. With the two images far away in disjoint parts of the 
visual cortex it would be hard to combine the information. Hmm, I wonder 
if the condition is more severe in man. IIRC the two halves of the brain 
do communicate more in women.

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