Although most flashes and floaters occur in people with healthy or merely nearsighted eyes, they can be symptoms of serious problems including injury and retinal and posterior vitreous detachments.
Flashes in vision are caused by pressure on the retina, the bundle of nerves in the back of the eye where images are detected and transmitted to the brain. When the vitreous gel rubs or pulls on the retina, you may see what look like flashing lights or lighting streaks. You may have experienced this same sensation if you have ever been hit in the eye and seen "stars."
The flashes of light can appear off and on for several weeks or months. As we grow older, it is more common to experience flashes. If you notice the sudden appearance of light flashes, you should contact us immediately in case the retina has been torn.
Floaters are often seen when fibers move within the vitreous humor, the gelatinous substance made of water and protein fibers that fills the eye. They appear as small specks or clouds moving in your field of vision. You can often see them when looking at a plain background, like a blank wall or blue sky. While these objects look like they are in front of your eye, they are actually floating inside. What you see are the shadows they cast on the retina, the layer of cells lining the back of the eye that senses light and allows you to see.
When people reach middle age, the vitreous gel may start to thicken or shrink, forming clumps or strands inside the eye. The vitreous gel pulls away from the back wall of the eye, causing a posterior vitreous detachment. This is a common cause of floaters. Posterior vitreous detachment is more common in people who:
- Are nearsighted
- Have undergone cataract operations
- Have had YAG laser surgery of the eye
- Have had inflammation inside the eye
Floaters can be a serious problem if the retina is torn, which can lead to a retinal detachment. You should make an appointment as soon as possible if you experience symptoms such as a new floater appearing suddenly, seeing sudden flashes of light, and/or loss of side vision. The appearance of floaters may be alarming, especially if they develop suddenly. You should contact us right away if you suddenly develop new floaters, especially if you are over 45 years of age.