What Affects Night Vision?

Problems with night vision is a very common problem. Most of the night vision problems, like halos, blurred vision, and night blindness, may be treated. Some of these may also be a sign of congenital medical condition, like retinitis pigmentosa. A number of other conditions, like exposure to the sun and nutritional deficiencies may affect normal night vision.

Here are some of the common causes of this condition:

• Cataracts – This progressive eye disease that gradually clouds the lens have reduced night vision as one of the earliest symptoms. Affected eye lens distort the light causing halos around images. Cataracts may also cause blurred vision and glare as clouding of the lens reduces the amount of light reaching the back of the eye.
• Deficiency of vitamin A – This vitamin is very essential for maintaining healthy retinas. People suffering from conditions like Crohn's disease, celiac disease, and cystic fibrosis may all have vitamin A deficiency with night blindness as the symptom.
• Zinc deficiency – Deficiency of this mineral may lead to blurred vision in the night as zinc is essential for vitamin A to be effective.
• Retinitis pigmentosa – This is a genetic disorder characterized by poor night vision as one of the early symptoms of the condition. In this disorder, retinal cells that help to distinguish light from dark, deteriorate and make night vision difficult. It usually starts at a young age and vision loss gradually worsens over years.
• Exposure to sunlight – Bright sunlight affects night vision for few days after the exposure. Wearing sunglasses while being out in bright sunlight as in a beach is the best way to prevent this condition.
• Complication after eye surgery – Some people report affected night vision after LASIK surgery. Formation of halos and glare are the two common vision issues seen after LASIK. Although these symptoms are felt more in the night, it may be present in daytime too.
• Diabetes – People with this condition have higher chances of getting night vision problems, when compared to others. Diabetes may lead to damage of the retina at the back of the eye. Poor vision after being in bright light for some time is one of the symptoms of retinal damage due to diabetes.
• Dry eyes – Dry eyes may lead to poor quality vision, particularly at night time.
• Uncorrected myopia – Blurred vision in the night is very common in people with uncorrected myopia. Even if the condition is corrected, it may be exacerbated by the dilation of the pupil at night.