Issue 18.14
Have you ever seen small moving spots in your eye? Maybe a thread or a fragment of cobweb drifting by? That’s a floater.
People usually describe floaters as gray, black or translucent. They vary in size and intensity. And they are more noticeable when there is a single color background like a white wall in a well-lit room, or a clear, blue sky.
Most of the time floaters are harmless, but in a small percentage of cases they can be a prelude to blindness. The only way to determine whether floaters are a serious eye problem or not, is to have an ophthalmologist look in your eye with a magnifying microscope. If you notice floaters, or a marked change in them, get to your eye doctor right away.
Floaters are caused by a change in the gel-like substance that fills the eyeball. As you know, the eyeball is spherical. On the outside, we can easily see the white part of the eye and the colored iris that surrounds the black dot of the pupil. But behind all that, inside the “ball” of the eye, is the gel-like substance called the vitreous humor (or vitreous, for short).
The vitreous is transparent, allowing light to pass from the front of the eye to the back of the eye. At the back of the eye, the retina receives the light. The retina interprets the light into an image and sends this information to the brain. But when clumps form in the vitreous, light cannot pass through them. These clumps are perceived as shadows on the retina, which we call floaters.
The vitreous tends to clump as we age. But everyone increases their risk of floaters if they have had an eye injury or eye surgery. People who are near-sighed with “long eyes” often develop floaters early in life. (Long eye occurs when the eye has a greater than normal distance between front and back, as measured from cornea to optic nerve). In any of these situations, the vitreous can begin to change. The gel-like material separates into semi-solid sections (clumps) and more watery sections. The clumps float around in the liquid areas; hence the name floaters.
When the eye is still, the brain can frequently tune out the shadows of these floaters by a process known as neural adaptation. But when the eye moves again, the floaters shift position slightly within the vitreous, registering as a shadow in a new place on the retina and sending a visual signal to the brain.
While floaters themselves are not harmful, their formation can create a more serious problem. When the vitreous first begins to clump, a person may see flashes of light. These light flashes are the result of the vitreous pulling away from the retina in places where it has become too firmly attached. If the vitreous pulls too hard on the retina, the retina could tear or break. This frequently leads to a condition known as a retinal detachment, which is a cause of blindness and requires immediate medical attention.
At this time, treatment for floaters is limited. It may be possible to use a YAG laser to break larger clumps into smaller pieces so that they are less noticeable in the eye. However, this type of treatment remains controversial among ophthalmologists. Surgical removal of the floaters is another option, but not generally recommended unless the floaters significantly interfere with essential daily functioning. Unfortunately, there are no drops or oral medications to treat floaters. But the good news is that most people easily learn to adapt and tolerate them, and floaters often become less noticeable with time.
If you’re interested in learning more about floaters from the ophthalmologist’s perspective, call Richens Eye Center to schedule your next comprehensive eye exam at (435) 216-1226.