Many conditions cause photopsia, or flashes of light in the eye. Flashes of light can be harmless, or an indicator of a serious eye problem that needs immediate treatment. See you doctor for an accurate diagnosis of the cause of light flashes in your eyes. Seek immediate medical attention if your flashes occur with vision loss or small specks that appear to float or dart from side to side in your vision.
Migraines -- severe recurrent headaches --last from a few hours to several days, often causing visual symptoms. Flashes of light that may look like zigzag lines, sparkles or geometric patterns often accompany migraines. Flashes usually appear in the peripheral areas of vision and may affect one or both eyes. Light flashes can also occur without headache, a phenomenon called an ophthalmic migraine.
Posterior Vitreous Detachment
The vitreous -- a gel-like substance that fills the center of the eye and gives it its shape -- attaches to the retina. Over time, the vitreous shrinks and begins to detach in places from the retina, a condition called posterior vitreous detachment, or PVD. The vitreous pulls on the retina as it detaches, stimulating the retina and causing flashes of light to be seen.
No treatment for PVD exists, however it should be monitored with regular eye exams. Symptoms of PVD mimic retinal detachment -- a condition that can cause permanent vision loss.
Retinal Detachment or Tear
Retinal detachment or retinal tears cause flashes of light that need prompt evaluation and treatment. Permanent vision loss can result if the retina detaches from the back of the eye, especially if detachment occurs over the macula -- the central point of vision on the retina. The retina loses its source of nutrients when it detaches from the eye. Because the retina contains the photosensitive cells responsible for vision, the consequences from cell death can be severe.
Retinal detachment can occur after trauma or as a complication from PVD or diabetes. Vitreous gel can seep under the retina through small tears or holes that occur from retinal thinning, raising up sections and disconnecting it from the eye, or a PVD can pull hard enough on the retina to pull parts of it away. Surgery, laser treatment or cryopexy -- a freezing technique -- all may be used to reattach the retina.
Trauma such as a blow to the head can cause a person to see flashes of light. Toxic levels of certain medications, such as Digitalis, can also cause flashes of light. These symptoms can also occur with macular degeneration -- an age-related disease that gradually reduces central vision.