Cataract: a condition in which a cloudy lens in the eye causes blindness.
Macular Degeneration: a condition caused by deterioration of the retinas; this is the most common cause of blindness.
It might creep in without you even noticing. One day, you'll look around and things seem a bit...blurry. Don't worry, you are not alone. Most people have difficulty seeing clearly and must use glasses or contact lenses. This includes many older people as well. This is because their eye muscles do not work as well as they use to and cannot focus light into their eyes correctly.
A lot of people think being blind means you live in a world of darkness. But that isn't always the case. Some people who can't see very well cannot use glasses to correct their vision – glasses won't help. Even if they are not completely blind, these people are referred to as Legally Blind.
Page Baluch, Ashleigh Gonzales. (2015, July 01). What Causes Blindness?. ASU - Ask A Biologist. Retrieved from https://askabiologist.asu.edu/fr/what-causes-blindness
Page Baluch, Ashleigh Gonzales. "What Causes Blindness?". ASU - Ask A Biologist. 01 July, 2015. https://askabiologist.asu.edu/fr/what-causes-blindness
Page Baluch, Ashleigh Gonzales. "What Causes Blindness?". ASU - Ask A Biologist. 01 Jul 2015. ASU - Ask A Biologist, Web. . https://askabiologist.asu.edu/fr/what-causes-blindness
Some people need to use glasses to see things clearly.