ADAM Health Encyclopedia

Vision - night blindness

Definition

Night blindness is poor vision at night or in dim light.

Alternative Names

Considerations

Night blindness may cause problems with driving in the evening or at night. People with night blindness often have trouble seeing the stars on a clear night.

Causes

• Cataracts
• Retinitis pigmentosa
• Vitamin A deficiency
• Certain drugs
• Birth defects

In some cases, the eyes may simply have trouble adapting to darkness. The problem may not be due to another medical condition. However, it is often linked to myopia (nearsightedness).

Home Care

Take safety measures to prevent accidents in the areas of low light. Avoid driving a car at night.

Vitamin A supplements may be helpful.

When to Contact a Medical Professional

It is important to have a complete eye exam to determine the cause, which may be treatable. Call your eye doctor if symptoms of night blindness persist or significantly affect your life.

Your health care provider will examine you and your eyes. The goal of the medical exam is to determine if the problem can be corrected (for example, with new glasses or cataract removal), or if the problem is due to something more serious.

The doctor may ask you questions, including:

• When did the night blindness begin?
• Did it occur suddenly or gradually?
• Does it happen all the time or just sometimes?
• How severe is the night blindness?
• Are you nearsighted?
• Do you have other vision changes?
• What other symptoms do you have?
• Do you have unusual stress, anxiety, or a fear of the dark?
• Does use of corrective lenses improve night vision?
• What medications do you use?
• How is your diet?
• Have you recently injured your eyes or head?
• Do you have a family history of diabetes?

A slit lamp examination may be done.