As part of the natural aging process, eyes lose the ability to see clearly under dim conditions, which risks the safety of drivers and those sharing the road.
“Safe operation of automobiles, motorcycles and recreational vehicles require split-second actions to stay on course,” says Dr. Thomas Harvey, an ophthalmologist and eye surgeon in Wisconsin.
The goal of a vision test at your state’s department of motor vehicles (DMV) is to verify your central and peripheral vision. Harvey says states set their own requirements for minimum daytime and nighttime vision. “The DMV devices are not used in doctors’ offices, and there is little information in the medical literature on their validity,” Harvey says.
That makes it possible for someone to pass a vision test given under daytime conditions but experience troubles seeing while driving at dusk or at night, according to Harvey. He says it’s smart to assess vision in a variety of light scenarios, not just a brightly lit DMV office.
With poor vision, you could, for instance, misjudge the distance between you and the car in front of you or you could misread the speedometer. In those circumstances, you could crash your car or get a traffic ticket. Both could cause your auto insurance rates to go up, depending on how many claims or traffic tickets you’ve got, according to Jennifer Nelson, an Allstate agent in New Jersey.
Here’s a look at three conditions that can affect your vision — and can affect your auto insurance premiums.
A condition that comes along with growing older, presbyopia limits your ability to focus clearly on close-up things or people. Dr. Michael Pier, an optometrist who is director of professional relations and practitioner education for Bausch + Lomb, says your state’s DMV doesn’t test for presbyopia; the screening gauges only distance vision. At the DMV, your eyesight usually is tested by reading a wall chart 20 feet from where you’re standing or by looking into a machine that simulates distance vision.
Dr. Harvey Fishman, an ophthalmologist in California, says presbyopia is common. “As the lens of the eye loses its ability to focus, numbers on a car’s instrument panel or the map on the GPS can become difficult to see. … Everyone will develop this at some point in their life, usually around age 45,” Fishman says.
One of the most common tests for presbyopia is holding a card with letters and numbers in different sizes at the normal reading distance, about 14 to16 inches away from the face, according to Pier.
Pier says this condition can lead to driving dangers because your eyes may be slow to adjust properly between near and far-away distances. “That means that reaction time may be affected. So someone relying on a GPS while driving may find it more difficult to move from focusing on the street names indicated on the GPS to focusing on the street names on the road,” he says.
Another common condition that hampers the ability to drive safely is cataracts, says Dr. Kurt Hofeldt, an optometrist at the Benson Eye Clinic in Washington. “Patients with cataracts will experience glare from headlights and streetlights or have trouble seeing street signs or the lines on the road,” Hofeldt says.
If it’s becoming difficult to read or watch TV and the glare of oncoming traffic is uncomfortable when driving at night, you may have cataracts, says Dr. Laura Green, director of cornea, cataract and refractive surgery at the Krieger Eye Institute in Maryland.
“Cataracts decrease the amount of light entering your eyes, and can cause blur and glare or light sensitivity,” Green says.
DMV vision screenings don’t check the health of your eyes, making it common for patients with cataracts to have decent daytime vision but poor nighttime vision, Green says. “In order to know if you have cataracts, you need a complete, dilated eye exam with a qualified eye doctor,” she says.
Night blindness is caused by an inability to adapt to dark conditions; it can develop as a result of age, vitamin deficiencies or disease. On the road, oncoming headlights can make the problem worse.
“You should always wear the glasses you’re prescribed for distance at night,” Fishman says.
DMV tests don’t take night blindness into account. If you think you may have this condition, talk to your eye doctor about prescription lenses, vitamins or surgical procedures as potential remedies.