I find it fascinating how they can go from regular eyeglasses to sunglasses out in the sun!
2007-01-15 07:27:18 · 3 answers · asked by JEFFAVEGRL 4 in Health ➔ Other - Health
UV Raditation causes them to darken. The reason these lenses darken in sunlight but not indoors under artificial light, is that room light does not contain the UV (short wavelength light) found in sunlight. Automobile windows also block UV so these lenses will not work very well in a car.
2007-01-15 07:36:00 · answer #1 · answered by lkb740 2 · 0⤊ 0⤋
Don't recognise approximately price of construction however the lenses are made with an additive that reacts to gentle in a reversable response, the extra severe the sunshine, the extra response there may be and the darker the lense turns into. I'm no longer certain what fabric supplies the response.
2016-09-08 04:01:11 · answer #2 · answered by hagenah 4 · 0⤊ 0⤋
i dont know but i love them!! they are awesome! search it on google or yahoo. look for wikipedia website in url
2007-01-15 07:35:31 · answer #3 · answered by Anonymous · 0⤊ 0⤋