Lots More Information Related HowStuffWorks Articles How Corrective Lenses WorkHow Your Eyes WorkHow Light WorksHow the Sun WorksHow Sunburns and Sun Tans WorkWhat is 20/20 vision?How do sunless-tanning products work?What is a "sunburn"?Is there a way to make my sunglasses scratch-resistant? More Great Links Corning Museum of GlassPlastics.orgTransitionsColor Lenses and PhotochromicsBerkeley Lab: Photochromic windows
