Photophobia is a symptom of abnormal intolerance to visual perception of light. As a medical symptom, photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of actual physical sensitivity of the eyes, though the term is sometimes additionally applied to abnormal or irrational fear of light such as heliophobia. The term photophobia comes from the Greek φῶς (phōs), meaning "light", and φόβος (phobos), meaning "fear".Patients may develop photophobia as a result of several different medical conditions, related to the eye or the nervous system. Photophobia can be caused by an increased response to light starting at any step in the visual system, such as:Common causes of photophobia include migraine headaches, cataracts, Mild Traumatic Brain Injury (MTBI), or severe ophthalmologic diseases such as uveitis or corneal abrasion. A more extensive list follows:Causes of photophobia relating directly to the eye itself include:Neurological causes for photophobia include:The best treatment for light sensitivity is to address the underlying cause. Once the triggering factor is treated, photophobia disappears in many but not all cases.People with photophobia will avert their eyes from direct light, such as sunlight and room lights. They may seek the shelter of a dark room. They may wear sunglasses designed to filter peripheral light and wide-brimmed sun hats.A study by Stringham and Hammond, published in the Journal of Food Science, discusses the improvement in visual performance and decrease in light sensitivity (glare) in subjects taking 10 mg Lutein and 2 mg Zeaxanthin per day.