Floaters and Flashes

Floaters and Flashes

You may sometimes see small specks or clouds moving in your field of vision. These are called floaters. You can often see them when looking at a plain background, like a blank wall or blue sky. Floaters are actually tiny clumps of cells or material inside the vitreous, the clear, gel-like fluid that fills the inside of your eye.

While these objects look like they are in front of your eye, they are actually floating inside it. 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. Floaters can appear as different shapes, such as little dots, circles, lines, clouds or cobwebs.  

When the vitreous gel pulls on the retina, you may see what look like flashing lights or lightning streaks. These are called flashes. 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 floaters and flashes as the vitreous gel changes with age, gradually pulling away from the inside surface of the eye.

Floaters and flashes are also caused by posterior vitreous detachment, where the vitreous gel pulls away from the back of the eye. This condition is more common in people who:
•   Are nearsighted;
•   Have undergone cataract operations;
•   Have had YAG laser surgery of the eye;
•   Have had inflammation (swelling) inside the eye.
•   Have had an injury to the eye.

The appearance of floaters and flashes may be alarming, especially if they develop very suddenly. To find out if a retinal tear or detachment is occurring, you should call your ophthalmologist right away if you notice the following symptoms, especially if you are over 45 years of age, have had an injury to your eyes or head, or if you have substantial nearsightedness:

  • A sudden increase in size and number of floaters
  • A sudden appearance of flashes
  • Having a shadow or curtain appear in the periphery (side) of your field of vision
  • Seeing a gray curtain moving across your field of vision
  • Having a sudden decrease in your vision

If the vitreous gel shrinks and pulls away from the wall of the eye, the retina can tear. This sometimes causes bleeding inside the eye that may appear as new floaters.

Some people experience flashes of light that appear as jagged lines or “heat waves” in both eyes, often lasting 10 to 20 minutes. These are not flashes from the vitreous gel pulling on the retina; instead, these types of flashes are usually caused by a spasm of blood vessels in the brain, called a migraine. If a headache follows the flashes, it is called a migraine headache. However, jagged lines or heat waves can occur without a headache. In this case, the light flashes are called an ophthalmic migraine, or migraine without headache. Contact your ophthalmologist if you experience these symptoms.

If you notice other symptoms, like the loss of side vision, you should call us right away.