"What causes one to see bright flashes in the dark?"

Question

I'm a 29 year old woman with good vision. But a few nights ago, when I was lying down to go to sleep, I saw a bright flash. At first I thought it was actually in my room, but I saw it a few more times with my eyes closed. This happened last night, too. What's wrong with me?

Answer

Any time you develop any visual symptoms, whether it be vision loss or flashing lights, make sure you see a qualified health care professional right away. In this case you may initially see a primary care physician, but you may end up needing to see an ophthalmologist or neurologist. Bright flashes of light without an actual light source can have several causes.

Probably the most likely in someone your age is a migraine headache. If this bright flash was followed by a throbbing headache a short time later, then a migraine is very likely. A phenomenon called retinal detachment causes a bright flash of light often followed by some vision loss. This usually occurs after head trauma. Finally a flash of light could be due to optic neuritis which is sometimes seen in patients who develop multiple sclerosis. Eye pain and loss of vision are the usual presentation of optic neuritis. I suggest that you schedule an appointment with your primary care physician first (as long as you can get in soon). He or she can take a detailed history and perform a thorough physical exam. Your doctor may decide (based on your exam) to refer you to either a ophthalmologist or neurologist depending on what the problem is likely to be. Good luck.