Is This Why You Can’t See at Night?

The lack of daylight in the evening can limit your ability to see and get around. But it doesn’t have to be that way.

Night blindness (nyctalopia), the inability to see well at night or in poor light, isn’t a disease, says ophthalmologist Bryan Roth, MD. “It’s a symptom of an underlying condition. In most cases, it’s treatable; in others, it’s not. Fortunately, severe forms of night blindness are very rare,” Dr. Roth says.

5 causes for night blindness

There are multiple reasons why you might have trouble seeing in the dark:

1. Nearsightedness can make it difficult to see well at longer distances in the dark, particularly if you don’t have strong enough glasses or contact lenses. “In that case, a new prescription might be all that’s necessary to correct your problem,” Dr. Roth says.
2. Certain medications can also cause temporary problems with night vision. “Some medications can alter the size of your pupils, which might make it difficult to see in low-lit conditions,” Dr. Roth explains. “There are also medications that slow down the eye’s ability to adapt from bright conditions to dimly lit conditions. This causes a temporary inability to see in the dark until the eye is able to adapt.” Talk to your doctor if you’re concerned about how your medications are affecting your vision.
3. Cataracts, which cloud the eye’s natural lens, are another treatable cause of night vision problems. “As a cataract forms, less light can enter the eye, which means you’ll need more light to see. “People with cataracts frequently complain of difficulties driving at night, glare with oncoming headlights, and difficulty driving in rain due to decreased contrast sensitivity.” Dr. Roth says. “Surgery to remove the cataract can resolve this problem.”
4. Nutritional deficiencies, such as a vitamin A deficiency, can also decrease your ability to see in the dark. “Vitamin A levels can be tested with a simple blood test and may be reversible with treatment” says Dr. Roth. Adding foods rich in vitamin A — such as carrots, dairy or mackerel — can often help restore your night vision.
5. Retinitis pigmentosa is one of several hereditary diseases that cause a permanent deficit in night vision. Since this condition is genetic, it can affect children as well as adults. Retinitis pigmentosa results in deterioration of the retina, which is the part of the eye that senses light. If you have this rare disease, you may have difficulty getting around because it also affects peripheral vision and can even cause problems in normal lighting conditions. There are lifestyle adjustments you can make, but unfortunately there’s not an effective treatment to stop or cure retinitis pigmentosa.

Adjusting to permanent night blindness

Most common causes for night blindness — except for causes like retinitis pigmentosa — are treatable, Dr. Roth says.

If you’re affected by permanent night blindness, it might be wise to adjust your lifestyle to accommodate your condition. Consider changing these:

• Find alternate transportation if you must travel at night.
• Carry an extra light source with you, like a penlight or small flashlight to help you see after dark.
• And if you have this condition, it’s important that you keep any appointments with your eye doctor.

When to call a doctor

“Many eye diseases have no symptoms, which is why I tell my patients it’s important to get a routine eye exam every year whether you think you have a vision problem or not,” Dr. Roth says. Regardless, if you begin to experience a progressive loss of nighttime vision, your condition is most likely correctable, so make an appointment for an eye exam.