Suddenly, zig-zagging lights appear in front of you, moving across your vision. They expand off to the side blocking your peripheral vision. For a while (20-30 minutes usually) there are parts of your vision that are completely blocked out. What is happening? Is it a stroke? Retinal detachment?
These symptoms are commonly seen during an ocular migraine episode. The visual hallucinations are thought to be caused by blood vessel spasms in the area of the brain that processes vision. During the episodes, areas in the brain are triggered giving you the illusion of a series of flashing lights. Sometimes, the visual effects are followed by a headache, other times they are not. The vast majority of the time, ocular migraines are completely harmless. They may be brought on by changes in the weather, stress, or certain foods and can develop at any age. Some get them very frequently, once every week or two, while others only notice them once in a while. As your vision is temporarily impaired during an ocular migraine episode, if one should happen while driving, pull over to the side of the road until it subsides.
As episodes of flashing lights can be indicators for other, more serious problems, we always recommend that you come in to see one of our optometrists any time you experience new visual symptoms of any kind. As well, any new headaches you experience should be evaluated by a medical professional. If there are other symptoms such as a droopy face, slurred speech, or inability to raise an arm seek urgent medical attention as these may be indicators of a stroke.