As of 2004, the National Eye Institute (NEI) reported blindness or low vision affects 3.3 million Americans over age 40 (or 1 in every 28 people), and by 2020 over 5 million people in the United States will have blindness or low vision. Although people 80 years of age were only 8 percent of the U.S. population (in 2004), they represented 69 percent of the blind people in the country.
Medical News Today reported (October 10, 2008) on the American Optometric Association's (AOA) 2008 annual survey. Although 81% of the respondents wear contacts or glasses (or both), 26% have not visited their eye doctor in 2 years. The AOA recommends annual eye exams for people over 60 years. Additionally, of the respondents who were 55 years of age and older, 72 percent first noticed visual changes between ages 40 and 45.
Macular degeneration ("an eye disease affecting the macula, the center of the light sensitive retina at the back of the eye, causing loss of central vision" from AOA Web site glossary) glaucoma ("a group of disorders leading to progressive damage to the optic nerve, and is characterized by loss of nerve tissue resulting in loss of vision" from AOA Web site glossary), and diabetic retinopathy ("a condition occurring in persons with diabetes, which causes progressive damage to the retina, the light sensitive lining at the back of the eye" from AOA Web site glossary) are generally age-related and can lead to permanent vision loss and/or blindness if undiagnosed and untreated. Additionally, comprehensive eye exams can detect signs of diabetes, hypertension, brain tumors, cancer, cardiovascular disease, and multiple sclerosis.
Just to clarify... reading in low light does not damage the eyes, nor does sitting too close to the television. Lastly, the most beneficial food for eyes and vision is not carrots! The best food is spinach, due to its lutein and zeaxanthin components that help fight cataracts and macular degeneration.
For More Information, References and Recommendations:
American Optometric Association
American Optometric Association glossary
American Eye-Q(R) Survey Indicates Strong Need To Educate Consumers About Eye Health
Eye News: Pediatric Vision Screenings, High Tech Solutions for Low Vision, Warning Signs and Symptoms
Visual Correlates of Stream Segregation, Scene Analysis, and Signal-to-Noise Ratio
National Eye Institute
http://www.nei.nih.gov/health/
http://www.nei.nih.gov/news/pressreleases/041204.asp