Night Blindness

Causes

There are several common causes of night blindness:

• Lack of vitamin A, which can cause a disorder of the retina and make the eyes very dry
• Cataracts, which are cloudy areas in the lens of the eye
• Some forms of retinal degeneration, such as retinitis pigmentosa
• Trouble adjusting from low levels of light to high levels of light
• Certain medications
• Birth defects

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Some risk factors for night blindness include:

• Age: elderly people are more likely to have cataracts
• Genetics: retinitis pigmentosa
• Diet: people who don’t eat enough sources of vitamin A, such as green leafy vegetables, eggs, and whole milk products (vitamin A deficiency is very rare in the US, but still occurs in certain less developed countries)
• Disorders that affect the ability of the body to absorb vitamin A:
  • Liver disorders
  • Surgery on the pancreas or liver
  • Intestinal conditions
  • Bowel surgery for obesity

Symptoms

Symptoms are difficulty or inability to see in low light or darkness. While driving, this may also occur a few seconds after the bright headlights of an oncoming car have passed.

Diagnosis

A doctor will give you a medical examination to determine the cause of your night blindness. Some of the things a doctor might do are:

• Ask detailed questions about your experience of night blindness
• Test the levels of vitamin A in your blood
• Give you an eye exam
• Ask about your medical history, including:
  • Diet
  • Medications
  • Use of corrective lenses
  • Family history of diabetes

Treatment

Depending on the reason for your night blindness, treatment will address the specific cause. Treatments generally include:

• Taking vitamin A supplements
• Having cataracts removed
• Low-vision aids

Prevention

If you experience night blindness, it is important to take safety precautions, like not driving in the evening or at night. Also, eating a diet with adequate amounts of vitamin A may help prevent night blindness.