Flashes are bright spots or points of light in your field of vision. You can develop flashes for a few reasons, but one of the most common is when the gel-like vitreous in your eye shrinks and begins to pull on your retina. This is called posterior vitreous detachment.
Why do I suddenly see flashes?
When the vitreous gel inside your eye rubs or pulls on the retina, you may see what looks like flashing lights or lightening streaks. You may have experienced this sensation if you have ever been hit in the eye and see "stars." These flashes of light can appear off and on for several weeks or months.
When should I worry about eye flashes?
If you're experiencing light flashes or other symptoms of photopsia, you should visit your doctor as soon as possible. Photopsia can be the first sign of eye conditions such as macular degeneration, retinal detachment, or vitreous detachment.