Jerry Avins <jya at ieee.org> wrote in message news:<3DF8929A.FD075AD4 at ieee.org>...
> jmdrake wrote:
> > ... The extra layers
> > of non-sensitive cells that the light must pass through before reaching
> > the sensitive cells acts like a "filter" to protect from UV radiation.
> > That's such a concern that human "engineers" have devised UV blocking
> > sunglasses to further block potentially damaging rays.
>> Those special UV-blocking lenses were invented not by engineers, but by
> advertising copywriters. Uncoated glass lenses block harmful UV.
> Coatings are needed only on plastic to bring them up to the standards
> set by glass.
Advertising copywriters typically don't invent anything.
> UV is also blocked from the retina by the vitreous humor. The greatest
> danger UV poses to unprotected eyes is to the lens. Inverting the retina
> can't help that. All the chordata have inverted retinas, including fish.
UV can also damage the retina, especially in young children.
With regards to fish that's irrelavent. The argument isn't about fish
versus celophods but man versus celophods. Whether fellow sea creatures
have different types of eyes neither adds no detracts from the
evolutionary argument. Actually nothing regarding celophod eyes
really does anything for the evolution argument unless you wish to
go with a "straw man" approach.
John M. Drake