Many people, at some time in their lives, notice floaters in one or both eyes. These are perceived as small spots or strands that seem to drift in the field of vision, traveling rapidly with eye movements and then floating slowly when eye movements cease. Floaters are most readily seen against a bright or plain background such as a blank wall or blue sky.
Light flashes may occur in conjunction with floaters or may occur separately. Unlike floaters, light flashes (photopsias) are typically perceived in subdued lighting or even total darkness. They can look like flashing lights or lightning streaks. Some people compare them to seeing “stars” after being hit on the head. Photopsias can range from minimal light twinkles to flashes that are bright enough to suggest a neon sign or camera flash. You might seem them on and off for weeks or even months. As people age, it is common for them to occasionally see light flashes.
Most occurrences of floaters or light flashes relate to changes in the jelly-like substance called vitreous which fills the entire back cavity of the eye. The vitreous is transparent and has a solid consistency similar to gelatin. As people grow older, the vitreous undergoes a normal aging process, becoming more liquid and less jelly-like. Often the partially liquefied vitreous will abruptly “collapse” inside the eye, causing a shower of floaters to appear. The floaters are tiny clumps of gel or cells which have formed in the vitreous during the liquefaction process. What you see are the shadows these clumps cast on your retina.
When the vitreous collapses, it begins to separate from the retina. The mechanical pull of the vitreous on the retina during this separation causes light flashes. Sometimes during this separation process, a retinal tear develops and can lead to a retinal detachment. Often when a retinal tear occurs, at least a small amount of bleeding is present in the vitreous and may be noted by the patient as a multitude of black dots or a hazy decrease in vision.
The sudden occurrence of floaters or flashes can be an important warning signal of impending retinal problems. A small percentage of people who develop the abrupt onset of prominent floaters or light flashes in an eye will be found to have a retinal tear.
Fortunately, the majority of people who experience floaters or light flashes do not develop serious retinal problems. In most instances, the floaters and flashes gradually subside over a period of time with no permanent alteration in vision. Since flashes and floaters can, however, be an important warning of a retinal tear or impending retinal detachment, their sudden appearance is of sufficient concern to warrant careful evaluation by your ophthalmologist. In addition, call your ophthalmologist right away if you notice:
You are more likely to get floaters if you have had one or more of the following:
Most of the time, floaters and flashes are diagnosed by the patient and confirmed through a dilated eye exam by your ophthalmologist.
Floaters are not serious, and they typically go away on their own over time. Severe floaters can be surgically removed, but this is rarely needed. If you experience flashes that increase in frequency, you should see your ophthalmologist to rule out a torn or detached retina. A retinal tear or detachment requires surgery to repair, and we have a number of physicians at Texas Retina Associates who are experienced in performing this procedure. Learn more about treatment for retinal tears/detachment.