If you’ve been having problems seeing at night, especially while driving, in movie theatres or other dark places, you could have night blindness. Night blindness is not a problem itself, but a symptom. Several conditions can cause night blindness, such as nearsightedness, cataracts, keratoconus, and a lack of vitamin A.
Nearsightedness (myopia) is a condition in which you can see close objects clearly, but objects farther away are blurry and you might have more difficulty seeing while driving a vehicle at night. Corrective lenses or refractive surgery are two ways of improving vision.
Cataracts cause sensitivity to light and glare, causing you to see “halos” around lights and making it more difficult to see at night. A cataract scatters and blocks the light as it passes through the lens, preventing a sharply defined image from reaching your retina and your vision becomes blurred. Keratoconus occurs when your cornea thins and gradually bulges outward into a cone shape. A cone-shaped cornea (the clear, dome-shaped front surface of your eye) causes blurred vision and may cause sensitivity to light and glare. Keratoconus usually affects both eyes and generally begins in people ages 10-25 years and may progress slowly for 10 years or more.
While some people are born with night blindness, it could develop from a degenerative disease involving the retina. A degenerative disease involving the retina usually can’t be treated, but if you do have it, you’ll need to be extra careful in areas of low light.
William C. Womble, O.D.
1822 Huntsville Hwy., Suite D