If you are not accustomed to it, seeing eye floaters, flashes, or spots can be alarming. In most cases, it is not a sign of a serious problem, but it can be. If you experience a sudden abundance of floaters or spots, you may have a torn or detached retina. Typically this is accompanied by seeing a bright flash or flashes of light. Seeing flashes or stars can be a symptom of an ocular migraine, or low blood pressure.
Eye floaters are little shadows that move across your vision. They are sometimes described as looking like cobwebs, little worms, flecks, spots, or squiggles. Floaters are little clumps of vitreous gel, and what you see are actually the shadows of these clumps. We tend to get more eye floaters as a natural part of aging. They are more noticeable when you are looking at the sky or a light colored background.
A sudden onset of floaters can mean that your retina is detaching or has been torn. Your eyes are filled with vitreous gel and, as you age, the gel thickens and shrinks. During this process it can pull away from the back wall of the eye. This is called vitreous detachment. In some cases this can lead to a torn retina or retinal detachment. If you suddenly have a large floater or a cascade of small floaters, see your ophthalmologist right away.
Flashes of light or stars can have a number of causes. Torn retina or retinal detachment can cause you to see flashes or stars with or without floaters. Migraines and ocular migraines cause blood pressure changes which can cause you to see flashes or stars. Standing up to quickly can quickly lower blood pressure to your head, causing you to see stars and feel dizzy.
You should see your ophthalmologist right away if you see sudden flashes along with new floaters or if you experience a loss of vision, such as loss of side or peripheral vision, after the flashes.
If you have had cataract surgery you may still have fragments of your natural lens in your eye causing you to see dark spots. Macular edema (swelling) can cause a spot in your vision. The macula is the center of your retina. Macular edema can occur in diabetic retinopathy, central serous retinopathy, cystoid macular edema, and blockage of the vein that drains blood from the retina.