Night Blindness

Night Blindness

WHEN TO SEE YOUR DOCTOR

* You're having sudden or increasing difficulty seeing in dim light.

* You're having difficulty driving at night or performing other activities because of glare.

* You're unable to see stars in the night sky that are visible to others.

What Your Symptom Is Telling You

The movie's theme song has started, the theater is pitch black and you're groping to find an empty seat. You're relieved to find yourself a good spot right in the middle without having tromped on too many toes. In a matter of minutes, you can see all 20 rows in front of you ( . . . and the creepy guy in the seat next to you!). That's how it should work. But if you still can't make out your popcorn bucket after five minutes or so, it means that your nighttime vision isn't all that it should be.

Poor night vision is fairly common, especially among people who are nearsighted, says George Sanborn, M.D., associate clinical professor of ophthalmology at the Virginia Commonwealth University/ Medical College of Virginia in Richmond.

Other possible causes include diabetes, cataracts, macular degeneration (an eye disease in which a part of the retina gradually falls apart) or an inherited eye disease called retinitis pigmentosa. In rare cases (rare in the United States, but common in the third-world countries) night blindness is caused by a severe vitamin A deficiency.

Symptom Relief

Here are some tips to help you see in low light.

Cut the glare. Your optometrist or optician can put an antireflective coating on your glasses that cuts glare and increases the light coming into your eye, according to Bruce Rosenthal, O.D., chief of low vision services at the State University of New York, College of Optometry in Manhattan.

Wear your specs. If you're mildly nearsighted and don't have to wear your glasses all the time, at least wear them after sundown, advises Dr. Sanborn.

Forget fluorescents. After age 60, many people find that they see better with the increased wattage of incandescent (yellow) lights rather than fluorescent lights, says Dr. Rosenthal.

Think bright. If your doctor diagnoses macular degeneration, you need all the light you can get, especially while reading, says Jason Slakter, M.D. attending surgeon in the Department of Ophthalmology at the Manhattan Eye, Ear and Throat Hospital. In the early stages of this disease, positioning an arc-type halogen reading lamp behind your shoulder is ideal for providing bright light where you need it.

Eat smart. There is evidence that the antioxidant nutrients can help control many conditions responsible for poor night vision, according to Mitchell H. Friedlaender, M.D., director of corneal services in the Division of Ophthalmology at the Scripps Clinic and Research Foundation in La Jolla, California and coauthor of 20/20: A Total Guide to Improving Your Vision and Preventing Eye Disease. Antioxidants work by counteracting naturally occurring tissue damage to the eye, he explains.

The key nutrients are vitamins A, C and E; zinc and beta-carotene, which is converted to vitamin A in the body. If your diet consists mainly of whole grains, fruits and vegetables, you should be getting the nutrients you need. But it's a good idea to ensure your intake with a daily multivitamin and mineral supplement.

Don't get caught in the headlights. Driving after sundown can be a challenge, especially when a stream of headlights is headed your way. "As a rule, you want to keep oncoming headlights in your peripheral vision so they don't momentarily blind you," says Dr. Slakter.

Wear sunglasses before entering tunnels. In daylight, putting on sunglasses about a mile before entering a dark tunnel helps your eyes get partially adapted to the dark, says Dr. Slakter. Once inside the tunnel, remove your sunglasses and you'll be able to see in the dim light.