Can wearing a hat really help you see better in the dark? How about an eye patch? Take these tips to maximize your night sight.

By Joseph D. Younger

During these long winter nights, you probably do most of your commuting in the dark. Do you ever wish that you could take a magic pill to see better?

Back in World War II, RAF pilots supposedly ate bilberries before bombing runs to improve their night vision. Nowadays, many health stores and Web sites hawk an extract from the blueberry-like fruit as a supplement. Although bilberries have lots of antioxidants and other good stuff, studies have failed to prove any vision benefits. So never mind the magic pills.

Unfortunately, you can’t do anything to genuinely improve your ability to see at night, say medical experts. Your rods and cones—the photoreceptors in your retina that work together to detect light at various wavelengths and intensities—are what they are. And your ability to see at night only deteriorates with age. For instance, a 50-year-old needs about twice as much light to see as well after dark as a 30-year-old. Even younger folks who don’t otherwise need glasses suffer a condition called “night myopia”—a tendency to nearsightedness under low-light conditions.

But you can learn to get the most out of what you’ve got. The tips below will help you see better—and drive better—when the sun goes down.

• Wear a hat and sunglasses during the day. Exposure to bright sunlight—especially at the beach or on the ski slopes—effectively “bleaches” the photoreceptors in your eyes and lengthens the time it takes them to adjust to the dark. Normally, your eyes reach full dark adaptation in about 30 minutes. But studies show that as little as two to three hours of bright sunlight can delay it by hours.  And the longer you stay in the sun, the worse your night vision gets. For instance, 10 consecutive days of full-sun exposure can reduce your visual acuity, range, and contrast discrimination at night by 50 percent.  Experts recommend wearing neutral-gray sunglasses and a hat with a brim during the day to maximize your vision at night.

• Take vitamins. “The photochemical reactions in the retina require a baseline level of certain vitamins, especially vitamin A,” says Dr. Jeffrey Weaver, clinical care director of the American Optometric Association. A multivitamin does the trick for most people, but your eye doctor or pharmacist can give you the 411 on specific vitamins required for healthy vision.          

• Make your windshield disappear.  If you can see your windshield—not through it—then it needs cleaning. “Clean your windows inside and out, especially the windshield, at least once a week,” says Barbara Ward of the Club’s traffic safety department. “Light is refracted through a dirty windshield, which intensifies glare. And you see less reflection in clean glass.” Wash your headlights, too, especially in winter. Even a thin layer of slush, snow or road grime can reduce the light they cast by as much as 90 percent. Don’t forget to wipe your wipers; streaks and smudges can make glare worse in the rain.

• Dim the dash lights. Your instrument panel has a rheostat for a reason. Keep it just bright enough for the instruments to remain safely legible. The dimmer the light inside, the better you can see outside. Think about looking outside your bedroom window at night. To see more outside, you turn out the lights inside, right? The same principle works in your car.

Did you ever wonder why some carmakers, most notably BMW and Pontiac, use red-lit instrument panels? Sure, they look cool. But there’s a sound physiological reason for the color choice as well. Red light’s longer wavelength doesn’t affect your retinal rods (those receptors most responsible for vision in dim light). Basically, red-lit instruments allow your eyes to maintain their full dark adaptation, so you can better see what’s happening beyond your windows.

• Look away, look away—not to Dixieland, but to the side of the road. When oncoming headlights shine into your eyes, fight the temptation to look directly at them. Instead, cast your gaze down and about 20 degrees to the right—at the white line marking the edge of the pavement. “You’ll still pick up motion with your peripheral vision,” notes AAA’s Ward, “and the glare won’t be as blinding.”

• Pump gas with one eye closed. We’re not kidding about this one. Pilots and other aviation personnel often cover one eye when looking into strong light at night. The technique helps recovery from “flash blindness”—the condition that occurs when a few seconds of brightness robs your eyes of night vision for a while. Although your eyes slowly adapt to darkness over 30 minutes or so, a short exposure to bright light undoes the process and “resets” the mechanism. You start all over again, slowly working your way back to full dark adaptation. But since the eyes adapt independently, shielding one from brightness preserves night vision in the protected eye.

Of course, AOA’s Weaver doesn’t recommend covering one eye against bright light as a behind-the-wheel technique. It would not only reduce your visual field, but also affect depth perception. He does suggest shutting one eye in harshly lit service plazas or parking lots, however. “You might even consider carrying an eye patch to wear in those situations on a long drive,” he says.

• Adjust your mirrors. Besides flipping your car’s center-mounted rearview mirror to its “night” setting, you can eliminate reflected glare from headlights behind you by adjusting your outboard mirrors properly, notes AAA’s Ward. It’s easy. While sitting in the driver’s seat, tilt your head until it rests against the window. Adjust the driver’s side outboard mirror so that you can just see the rear fender at the edge of the glass. Then sit upright again and do the passenger’s side. Tilt your head to the right until it’s approximately in the center of the vehicle. Again, adjust the outboard mirror so that you can just see the rear fender at the edge of the glass. These settings not only eliminate blind spots, but also keep the brightest portions of trailing cars’ headlights from shining directly into your eyes.  

• Wear eyeglasses with anti-reflective coating. If you wear prescription glasses, you’ll definitely notice a big difference with an anti-reflective coating. “A typical lens—even a clear one—will reflect 8 to 10 percent of white light incident upon it,” explains Weaver. On the other hand, lenses with an anti-reflective coating transmit more than 99 percent of light and eliminate internal reflections. Although the coating does make your glasses more prone to scratches and smudges, recent improvements in chemistry and technology have made newer coatings far less finicky than older ones.

And forget about those yellow-tinted, “blue-blocker” lenses that supposedly improve contrast in low light. They do block lower-wavelength light—but at night, lower-wavelength (blue) is the only light available. Since you need all the light you can get after dark, yellow lenses actually make your night vision worse.