Four score and thirty minutes ago, I thought of this idea. We should take the concept of those eyeglass lenses that darken in the presence of strong light and apply it to contact lenses.

Only the area around the pupil would darken so your eyes wouldn't look like brown splotches and as an added bonus, if you ever lost one, you could just shine a strong UV light over the area. The reason behind this is that contrasting lenses actually react to UV radiation instead of visible light. That is why they do not darken when you are inside.
-- DesertFox, May 13 2004

Contact sunglasses http://www.halfbake...ontact_20sunglasses
discussed here [FarmerJohn, Oct 05 2004, last modified Oct 17 2004]

Visiontech Services http://www.vstk.com/photoChr.htm
Makers of photochromic contact lenses. I read elsewhere they've not yet received FDA approval for US sale. [dpsyplc, Oct 05 2004, last modified Oct 17 2004]

Light Sensitive Contracts, now that's an idea
-- theircompetitor, May 13 2004


How would they know the location and size of your pupil?
-- bristolz, May 13 2004


I see now that these are available, but I think you still have to import them yourself from Asia. <link>
-- dpsyplc, May 14 2004


Bristloz, measure the size of your pupil. If the same amount of light comes through all the time because of darkening, then your pupil will stay pretty much the same size.
-- DesertFox, May 14 2004


That's not true [DesertFox] different people have different size dilation given the same light levels.
-- bristolz, May 15 2004


I said measure YOUR pupil. That was for you, not for Bob down the street.

What I meant was as the contacts darken, they let the same amount of light in because they just block the excess light.
-- DesertFox, May 15 2004


Oh nevermind.
-- bristolz, May 15 2004


I know what you meant.
-- DesertFox, May 15 2004



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