Re: Stupid question ...

On Fri, 08 Apr 2005 00:35:22 -0500, William Hamblen
<wrhamblen@xxxxxxxxxxx> wrote:

>Your natural lens is slightly yellow, so you will get a color shift
>after it is removed. Implants are tinted to match. Cataract glasses
>usually were tinted. I think Houston did not have implants. You can
>still focus a telescope without wearing cataract glasses and the color
>shift would be detectable.

Your natural (healthy) lens is water clear. As a cataract develops, it
yellows. Intraocular implants are also completely clear. Natural lenses
absorb UV, and implants these days are also designed to absorb UV.
However, before about 10 years ago many implants were relatively
transparent to UV compared with a natural lens.

While it is possible that some people saw a color shift due to UV
sensitivity, it is more likely they were just seeing the difference
between yellow before and clear after, and interpreting that as blue.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
.