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Re: a link to some interesting illusions



Hi,
I once talked with an older observational
astronomer who had a cornea replaced. He claimed
to see deeper into the UV with the replacement.
Somehow I think the corneas were synthetic, but my
memory, after almost 20 years, is a bit vague. I
do remember that holes for the stitches were
visible and he figured out a different stitch
pattern that would use the eyes blind spot to hide
them better. It may be that corneas were human,
and he could see UV through the stitch holes.

Thanks
Roger Haar U of AZ

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Bernard Cleyet wrote:

I suspect all mammals do.

Easy to check (for the smart ones). I discovered this when aligning a
monochrometer illuminated by a D2 lamp. Since then I've done it a few
times with an Hg pen lamp. Beyond the violet the color is a blue tint
(low purity) and spread unfocussed over the whole field, I don't
recommend doing this for more than a few sec.. The first time; I "sun
burned" my eye -- very painful and may contribute to macular
degeneration.

Is it bees that do? -- in that case I suspect their receptors are UV
sens. -- mammals, may be, also, but the cornea, lens, aqueous, and
vitreous absorb it.

bc

Larry Smith wrote:

At 1:14 PM -0800 2/4/03, Bernard Cleyet wrote:
bc who sees UV, presumably because his cornea fluoresces.

Is this how other species see UV? How many humans can?

Larry