Richard L. Hall wrote:
>> How many vertebrates lack eye lenses? Fish have them as do all
> tetrapods that I know of. So maybe the answer is zero. There are
> some species that have greatly reduced eyes and presumably greatly
> reduced optic tracts. Still, so many other central systems
> decussate, that it seems unlikely that something like the formation
> of a lens could account for crossed visual pathways.
[Hammond]
So far as I know, animals that can see but without lenses,
e.g. "compound eyes", have ipsilateral CNS structure...
there is no decussation... further support for the theory.
Take a fruit fly for instance.
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George Hammond, M.S. Physics
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