Light sensitivity, also called photophobia, is a sensitivity or intolerance to light. Light sensitivity may occur with sunlight, fluorescent light or incandescent light. Sometimes light-sensitive people are bothered only by bright light.

Causes
Usually photophobia is a symptom of another underlying problem, such as a corneal abrasion, uveitis (inflammation of the inner portion of the eye), or a central nervous system disorder such as meningitis. Light sensitivity may also accompany retinal detachment, contact lens irritations, sunburn and refractive surgery. People with lighter-coloured eyes, cataracts and those who suffer from migraine headaches notice more sensitivity to light and glare.

You may experience photophobia if you're diagnosed with any of the following conditions: albinism, total colour deficiency (seeing only in shades of grey), botulism, rabies, mercury poisoning, conjunctivitis, keratitis or iritis. Some medications may cause light sensitivity as a side effect, including belladonna, furosemide, quinine, tetracycline and doxycycline.

Symptoms
The main symptom of photophobia is a need to squint or close your eyes in bright light. Headache may also accompany light sensitivity.

Most Common Treatments
The best treatment for light sensitivity is to treat the underlying cause. In many cases, once the triggering factor is treated, photophobia disappears. The same holds true for medications causing light sensitivity. Discontinue the medication, and normal tolerance of light is returned. Discuss possible side effects with your prescribing physician before discontinuing any medications.

Avoid bright sunlight and other bright lights if you're sensitive to light. Wear wide-brimmed hats and appropriate sun protection on your eyes. Be sure your sunglasses have ultraviolet (UV) protection. While wearing sunglasses, your pupil dilates to allow more light to enter your eye. Additional harmful UV rays enter as well.

Keep in mind that light sensitivity may be allowing your eye to heal, especially in cases of photophobia associated with refractive surgery, corneal abrasion and other eye conditions. Light sensitivity is frequently a natural defence when the eye is traumatized.

http://www.eye-care.org.uk