Night blindness, or nyctalopia, is rare in the United States; however, according to the Mayo Clinic, it is a concern in developing countries where malnutrition is common. Night blindness is characterized by the inability to see clearly in poor light, or at nighttime, as the eyes have trouble adapting to the darkness. Night blindness may be treatable, and a complete eye exam can determine the cause and best course of treatment.
Vitamin A Deficiency
Vitamin A is a fat-soluble vitamin that mainly comes from animal sources, including liver, kidney, eggs, meat, milk and cheese. Carotenoids found in plant foods such as carrots and pumpkins can turn into a form of vitamin A in the body. The U.S. Department of Agriculture recommends males and females aged 14 and older receive 900 and 700 mcg a day, respectively. Not reaching those recommendations could cause night blindness as vitamin A is important in the production of retinol. Retinol produces pigments in the retina of the eye and vitamin A promotes good vision especially in low light.
Retinitis Pigmentosa
Retinitis pigmentosa is a genetic disorder that is characterized by progressive damage to the retina. According to the National Library of Medicine, it affects about one in 4,000 Americans. The cells most often affected in the eye are those that control night vision. This condition can have have an onset at any time, including childhood. As the disease progresses, peripheral, or side, vision is lost and can continue to progress until complete blindness occurs. A color vision and complete eye exam can help diagnose this condition, but there is no effective treatment available.
Cataracts
Cataracts is a condition where the lens of the eye becomes cloudy; it is another cause of night blindness. According to the National Library of Medicine, excessive sunlight and excessive exposure to smoke and other toxic substances may increase the risk of developing cataracts. Inflammation diseases, radiation exposure, cortisone and other medications can also increase cataract formation. Some people develop cataracts in only one eye, or both eyes can be affected. Cataracts is a treatable condition, and surgery may be necessary.
