New Contact Lenses Can Turn Dark On Sunny Days

[ahlam1399]

http://img-s-msn-com.akamaized.net/tenant/amp/entityid/AAvXwVW.img?h=100&w=100&m=6&q=60&o=f&l=fThe U.S. Food and Drug Administration officially giving its seal of approval to the first contact lenses which incorporate photochromic elements. Photochromic sunglasses which can darken or lighten depending on how much ultraviolet radiation they come into contact with have been around for years. Thanks to a special additive, the new contact lenses will automatically darken when theyâ??re exposed to bright light while becoming clear again in normal or dark lighting conditions. As such, they offer vision correction that will continuously balance their tint to control the amount of light entering each eye.

أكثر... (http://www.msn.com/en-in/health/video/new-contact-lenses-can-turn-dark-on-sunny-days/vi-AAvXwVY?srcref=rss)