eyes, flashing lights in the

eyes, flashing lights in the Spontaneous flashing-light sensations in the eyes that can be caused by a number of factors. A sensation of flashing lights can be caused when the vitreous humor (the clear, jelly-like substance that fills the middle of the eye) shrinks and tugs on the retina. These flashes of light can appear off and on for several weeks or months. With age, flashes become increasingly common. Flashes usually do not reflect a serious problem. However, if one notices the sudden appearance of light flashes or a sudden increase in flashing lights, one should see an ophthalmologist immediately to see whether the retina has been torn or whether there is another cause. Flashes of light that appear as jagged lines or “heat waves” in both eyes, often lasting 10 to 20 minutes, are different from these benign flashes. They are usually caused by migraine, a spasm of blood vessels in the brain. These jagged lines can also occur without a headache, in which case they are termed ophthalmic migraine or migraine without headache. Treatment may or may not be necessary depending on the cause.