Photophobia

Photophobia is a condition where a patient becomes overly sensitive to light and generally cannot tolerate any light above what might be normal in a darkened room.  The term is also used to describe patients who are adverse to sunlight or other well lit places.  Patients describe a sensation of discomfort or pain when exposed to high light levels and don't actually have a fear of light itself. 
Photophobia is a symptom of many diseases, including rabies, porphyria (particularly erythropoietic protoporphyria), benzodiazepine withdrawal, conjunctivitis, encephalitis, hangover, mononucleosis, meningitis, mercury poisoning, and migrane headache, to name a few.
Photophobia at Wikipedia
Category:Symptoms