Small specks and flashes of light in the field of vision

Sometimes people see small spots or specks moving in their field of vision or experience flashes of light. These occurrences are called floaters and flashes. Although annoying, floaters and flashes are generally of little importance. However, in some cases, floaters and flashes may be the symptoms of a more serious eye problem, such as retinal detachment.

What Is a Floater?
A floater is a small clump of gel that forms in the vitreous, the clear jelly-like fluid that fills the cavity inside the eye. Floaters may be seen as dots, lines, cobwebs or spiders and are most often noticed when reading, looking at a blank wall, or gazing at a clear sky.

Although floaters appear to be in front of the eye, they are actually floating in the fluid inside the eye. Sometimes, floaters do not interfere with vision at all. However, when a floater enters the line of vision, light is blocked and a shadow is cast on the retina. (The retina is the thin lining at the back of the eye that converts images to electrical impulses which are then sent by the optic nerve to the brain.)

What Causes Floaters?
The appearance of floaters may cause much concern, especially if they develop suddenly. However, floaters are usually a result of the aging process. As we mature, the vitreous gel shrinks and pulls away from the retina. Floaters are formed from the reorganization of the vitreous material and from some fragments of the retina which have been pulled into the vitreous cavity.

Floaters are especially common in nearsighted people, in people who have suffered eye injuries, and after eye surgery. Although uncommon, floaters can also result from inflammation within the eye or form crystal-like deposits which form in the vitreous gel.

Are Floaters Ever Serious?
Sometimes, the retina may be torn as the vitreous shrinks and pulls away from the retina. A tear through a small blood vessel in the retina may cause bleeding. Clotted blood and vitreous material may appear as a new set of floaters. Retinal tears require immediate medical attention to prevent retinal detachment. If the retina detaches from the back of the eye, partial or total loss of vision may occur.

How Are Floaters Treated?
Although annoying, floaters usually do not threaten vision and do not require treatment. Often floaters diminish and become less bothersome with time. If a floater appears directly in the line of vision, moving the eye around will often help. Looking up and down or back and forth will cause the vitreous fluid to swirl around and often allows the floater to move out of the way. However, with a complete eye examination, it can be determined if the floaters are harmless or the beginning of a more serious problem.

In cases where floaters do indicate a more serious condition, lasers can be used to prevent vision loss. Retinal tears can be sealed with an Argon laser. This painless treatment can usually be performed as an office procedure and prevents more serious conditions, such as retinal detachment.

What Are Flashes?
Flashes appear as flashing lights or lightning streaks in the field of vision, although no light is actually flashing. Flashes are similar to the sensation of "seeing stars" when one is hit on the head. Flashes are most often noticed at night or in a dark room.

What Causes Flashes?
Flashes are caused by the vitreous gel tugging on the retina. If the gel actually separates from the retina (posterior vitreous detachment), flashes of light may appear periodically for several weeks. As with floaters, flashes are usually a result of the aging process and do not indicate a serious vision problem. However, flashes that appear along with a large number of new floaters or with a loss of part of the field of vision may indicate retinal detachment, requiring an immediate eye exam.

Flashes can also occur in association with migraine headaches. A migraine is caused by a spasm of blood vessels in the visual information center of the brain. Migraine-related flashes distort central vision for 10 to 20 minutes and appear as jagged lines or "heat waves" in both eyes.

How Are Flashes Treated?
Unless they represent the symptoms of a more serious condition, flashes do not require treatment. Flashes that are a result of the vitreous pulling away from the retina will eventually stop. However, flashes may indicate retinal detachment, which needs immediate medical treatment. Migraines, which are often accompanied by flashes, can be treated with medical therapy if they occur frequently and are debilitating.

Prevention Is the Best Medicine
Although floaters and flashes are usually not considered serious vision problems, one should have a complete eye examination to determine their importance. In most cases, treatment is not necessary. However, early detection and treatment of serious problems, such as retinal tears, can prevent permanent vision loss.

If you are experiencing floaters, flashes or other vision problems, you should obtain a complete eye examination.