Have you ever left your brightly-lit home after hours only to find yourself unable to see anything in the dark? In many cases, your eyes adjust quickly to the lack of light, allowing you to see what you are doing and where you are going. But some folks find that their eyes take awhile to adjust. . .or that they don’t adjust at all. While this “night blindness” is at best a serious nuisance, it can be quite dangerous, particularly if a sufferer plans to drive after dark.
Night Blindness (nyctalopia)
While darkness will impede anyone’s vision, those who have unusual difficulty seeing in low light are said to have night blindness. Vision experts are quick to note that night blindness is not itself a disease, but a symptom of an underlying problem and is often, but not always, quite treatable. If you find that you have difficulty seeing at night or in dim light, an eye exam can help identify what’s causing your vision issues.
Incidentally, aging also affects night vision, so it’s important to pay attention to your vision as you age: Even if you had great night vision in your 20s, by the time you are in your 50s, you are likely to notice a decrease in your ability to see at night. Your eye doctor can help you determine a course of action if you fear that your nighttime vision is deteriorating.
In rare cases, night blindness can be caused by a vitamin A deficiency, though if you’re eating an adequate diet, it is unlikely that this is what’s causing your problem. Night blindness can also be a side-effect of using certain medications, including some antihistamines and anti-psychotics, so be sure to tell your eye doctor if you are taking any drugs, as this can aid in the diagnosis and treatment of your condition.
The most common treatable causes of night blindness are nearsightedness and cataracts. Cataracts can be treated with surgery and nearsightedness with glasses, so don’t delay scheduling an exam for diagnosis and treatment. In both cases, early diagnosis and treatment can save you a lot of inconvenience, as well as the risk of injuring yourself or someone else because you have difficulty seeing in the dark.
Some cases of night blindness can’t be treated, unfortunately. Birth defects can cause night blindness, as can retinitis pigmentosa, a condition in which the retina is damaged. Treatment for retinitis pigmentosa is limited, though many sufferers wear sunglasses to protect their eyes from damaging sunlight. Vitamin A is sometimes used to treat retinitis pigmentosa as well, though its side effects can be serious and the treatment is not always advisable.
All states administer vision tests to people applying for driver’s licenses, but these tests don’t always catch things like night blindness. Applicants with impaired vision might be issued a restricted license that only permits the driver to operate a vehicle in daylight, although it is sometimes possible to take a nighttime driving test to get around this restriction.
(In the UK, driver’s are required to inform the authorities of known night blindness. Those that don’t face a significant fine.)
If you drive, be honest with yourself about your night vision, and either get treatment for night vision issues or refrain from driving after dusk. If you do have a driving restriction, you may be able to take advantage of public transportation programs that serve the disabled, so contact your local public transit agency to find out if you qualify for reduced fares or special transit services.