Photophobia is an abnormal sensitivity to, and discomfort from, light. A person with photophobia experiences the same sensation in normal light that most people experience when they exit a dark room (such as a theater) into bright sunlight -- pain and discomfort. Unlike persons with normal vision, however, the eyes of persons with photophobia are unable to adapt to changing light conditions.

Causes of photophobia
Photophobia can be a symptom of a variety of diseases or a reaction to any of several different drugs. Any situation that causes the pupil to dilate (enlarge) and allow an excessive amount of light to enter may cause the condition. The most common cause of photophobia is inflammation of the anterior region (front) of the eye, which includes the iris. The iris controls pupil size and adjusts the amount of light entering the eye, and when the muscles of the iris are inflamed, it painfully constricts when light hits the eye.

People with light-colored eyes and those who suffer with migraine headaches experience more light sensitivity and glare, as do individuals who have been diagnosed with albinism, total color deficiency, a central nervous system disorder (such as meningitis), or botulism. Corneal abrasions can also cause light sensitivity, as can uveitis, an inflammation of the inner portion of the eye.

Certain retinal conditions, such as a Acute Catarrhal Conjunctivitis, retinal detachment, are also associated with photophobia. Another common cause is cataracts, a condition that occurs when the eye's natural lens becomes cloudy. The photophobia in this situation is easily eliminated by removing the Cataracts.

Treatment of photophobia
The best treatment for light sensitivity is to address the underlying cause. Once the triggering factor is treated, photophobia disappears in many cases. If medication is causing light sensitivity side effects, discontinuing the drug will normally solve the problem. Patients should wear sunglasses with ultraviolet protection and a hat with a brim to decrease the symptoms. Light sources should be shielded to prevent direct light into the eyes, and sources of glare in the environment should be eliminated.