What are floaters?
At some point in their lives, many people see what looks like small specks of dust or wispy threads drifting across their vision. They notice, however, that blinking does not get rid of the specks or threads. And when the eye moves, the specks or threads move too. These are called floaters.
Why do people get floaters?
There are a few different types of floaters, and each has its own cause. In general, though, eyes that are injured, inflamed, or nearsighted (cannot see objects far away) are more likely to get floaters.
The jelly-like fluid in the posterior chamber, which is the space between the back of the iris and the front face of the vitreous, is surrounded by a very thin membrane. The fluid also contains many fibers that are usually invisible. This whole structure is called the vitreous body.
Sometimes the fibers in the vitreous body pull loose from where they are normally attached. When this happens, they can make shadows inside the eye. This is what causes the floaters that look like wispy threads.
Very rarely, something that looks like a floater turns out to be tiny droplets of blood from the inside lining of the eye. This could be caused by an injury or by several conditions of the eye. When there is bleeding, there is a greater danger of losing vision.
When are floaters dangerous?
There is no way of knowing the cause of floaters without a careful examination. This is why it is important for anyone who starts seeing floaters to schedule an appointment with their eye doctor as soon as possible.
Most of the time, floaters are not the sign of anything dangerous. Floaters caused by loose cells, for example, are usually not that bothersome and often go away on their own in a few weeks or months.
The floaters that look like wispy threads tend to be more visible, and in most cases they will also go away with time. In some cases, however, they can signal other problems.
The fibers that cause the wispy-thread type of floaters are usually attached to the inside of the back of the eye. This surface is called the retina, and it contains the special nerve cells that react to light.
When the fibers of the vitreous body separate from the retina, floaters in a small area of vision are usually the only problem. In some eyes, however, many of the attachments between the vitreous body fibers and the retina will be broken.
Most floaters are caused by a posterior vitreous detachment. This occurs when the jelly-like fluid in the eye liquefies with age.
Sometimes the vitreous body fibers can pull some of the retinal nerve cells with them, causing a retinal tear that can lead to a retinal detachment. This can cause significant damage to vision. (More information about this condition is available in the "Retinal Detachment" fact sheet from the Cole Eye Institute.)
Can floaters be treated?
Only after a careful examination can your doctor give advice about possible treatment for floaters. In many cases, the examination will confirm that the floaters are not a symptom of a more dangerous condition. The doctor might just recommend that the patient have eye examinations more frequently to make sure that the eye with floaters does not get any of the more serious conditions later.
What are flashes?
Sometimes when vitreous body fibers pull on the retinal nerve cells, the eye has the sensation of a flash of light. This can be a small flash in just one spot, or it can be several flashes across a wider area of vision. It is not unusual for flashes and floaters to occur at the same time.
Are flashes a symptom of a more serious eye problem?
Flashes can be a symptom of a retinal detachment, which can damage vision significantly. Anyone who experiences flashes should see their eye doctor as soon as possible. If the flashes have been caused by a retinal detachment, the doctor will be able to give advice on possible treatment options.