Cataracts develop on the lens of the eye which is the first structure inside of the pupil.  It's okay to have a cataract as they are not considered clinically significant until they result in a visual acuity of 20/40 or worse.  However, many patients opt to have them treated prior to this level of acuity loss due to halos, glare, and other aberrations usually experienced while driving at night. Everyone over the age of 55 has one, but proper management of health as well sunglasses can prevent the progression of them.  Recently, practitioners have suggested that certain coatings even on computer glasses can possibly make a viable impact. http://www.gunnars.com/

There is no way to quantify the impact of sunlight exposure on our eyes as there are too many variables that limit the studies, but clearly there is a very strong relationship as the prevalence of cataracts and macular degeneration is far greater in tropical areas of the world.  This can be appreciated even here in the sunshine state of Florida.  It's important to protect your eyes from the ultraviolet free radical formation and oxidative stress resulting from excessive sunlight exposure,  The first option is SUNGLASSES. Sunglass compliance can (believe it or not) delay or even prevent the need for cataract surgery and many practitioners (including myself) believe that they can be a major difference maker in macular degeneration.  Age Related Macular Degeneration is truly devastating as our baby boomer population is hoping for a cure.  Even with shots to the eye becoming a norm, we are finding that a good diet along with clean bill of health are the only truly promising forms of treatment.  Say no to fried, greasy foods and yes to sunglasses as these good habits represent the most intrinsic forms of practicing good ocular health.