Have you ever spotted a small speck, dot, or squiggle floating in the air, only to have it flit away when you tried to look at it directly? Or have you noticed flickering lights or lightning streaks that you knew weren't really there? If so, you are one of many people who have experienced the common vision phenomenon known as eye floaters and flashes.

The majority of people — 7 out of every 10, in fact — will experience eye floaters and flashes at some point in their lives. They are a normal part of the aging process and, most of the time, not considered a medical problem. However, a rapid onset of many eye floaters and flashes could indicate that a retinal tear has occurred; if not treated immediately, this could cost you your eyesight.

Why Eye Floaters and Flashes Occur

Our eyes are filled with a clear substance known as vitreous gel that helps the eyeball keep its shape while allowing light to pass through to the retina; the retina is located on the eye's back wall and contains nerve cells that perceive visual signals from light. Eye floaters and flashes are caused by changes in the vitreous gel that occur as we get older.

Eye floaters occur when the vitreous gel thickens or shrinks due to aging, causing particles to form in the gel. These particles block the light passing through your eye, casting shadows on the retina. The shadows are seen as floaters, which can be created by:

  • The formation of protein clumps in the vitreous gel. These types of eye floaters tend to look like squiggles, cobwebs, tadpoles, or circles. They remain in the vitreous gel permanently, and people tend to ignore them.
  • The bursting of blood vessels in the retina as the shrinking vitreous gel pulls on them. Eye floaters caused by this kind of minor hemorrhaging create little black dots in your field of vision, which can resemble smoke or a cloud of gnats. They usually resolve themselves as the blood is reabsorbed by the body, but can last for months.
  • Posterior vitreous detachment (PVD). The vitreous gel actually pulling away from the retina is a condition known PVD. Debris from the site of the detachment drifts into the vitreous gel and causes floaters that resemble cobwebs, mist, or a veil that obscures part of your field of vision. In most cases, the detachment occurs cleanly and the eye floaters become less noticeable after a few months.

Eye flashes result from thickened vitreous gel pulling and rubbing on the retina, causing visual effects that look like lightning streaks or light flickers. These flashes may appear off and on for a few weeks or months, but normally fade over time. If you see flashes accompanied by floaters, you most likely are experiencing PVD.

Flashes also can be caused by an oncoming migraine headache. In these instances, the eye flashes often will look like jagged lines or heat shimmers that last between 10 and 20 minutes.

Time Is Your Best Treatment

Eye floaters and flashes caused by the vitreous gel are most visible when you are looking at a plain, light-colored background. Close one of your eyes and look at an empty wall, a blue sky, or a white background on a computer screen. If you see a squiggle, dot, or other shape flitting around, then you have found an eye floater.

Eye floaters and flashes normally require no treatment. Flashes usually fade away, and over time most people don't notice floaters as often because the brain learns to filter out the visual interference. An annoying floater in the center of your vision sometimes can be relieved by rolling your eyes around, which swirls the vitreous gel in the eyeball and gets the floater to move away.

A surgical procedure called vitrectomy removes the vitreous gel from the eye and replaces it with saline solution, but it is a major procedure that normally is not considered worth the risk.

When Retinal Detachment Is the Problem

The tugging from the vitreous gel can sometimes cause a more serious medical condition in which the retina tears and detaches from the eye. If this occurs, you could partially or completely lose your vision in that eye. Symptoms of retinal detachment include:

  • A sudden increase in the number of eye floaters and flashes you are experiencing, or the sudden appearance of them for the first time.
  • The loss of your peripheral vision, usually appearing like a curtain or shadow that moves toward the center of your vision over time.
  • Vision that has become blurred or distorted.

Surgery is the only treatment for retinal detachment, and time is of the essence in preserving your vision. If you are experiencing any of these symptoms, you should see your eye doctor immediately.