Eye floaters can be a highly annoying visual disturbance. Most of the time, a few floaters in your line of vision aren't harmful, but occasionally floaters, especially if they're large, numerous and develop suddenly, can be a sign of a problem in the back of the eye, arising from the vitreous or the retina.
Diagnosis
Floaters are easy to self diagnose. You may think that there's something on your eye or in the air. Floaters are more noticeable when you're looking at something light colored and plain, like a white wall. Ophthalmologists can diagnose floaters both from your description and by dilating your eye and looking at the back of the eye through an ophthalmoscope. There are some rare causes of floaters, such as inflammation of the eye (uveitis) so it's important to see an eye doctor if floaters suddenly appear.
Symptoms
A floater is a speck or string that appears within your line of vision. Floaters may move, or they may stay stationary. A large floater that doesn't move can be extremely disturbing, especially if it impacts the central part of your vision. Normally, floaters move with your eye, so they appear to be drifting if you try to focus on them. Over time, floaters settle onto the bottom of the vitreous, where you can no longer see them, according to the Mayo Clinic.
Sometimes floaters are accompanied by flashes of light; this indicates that there's a more serious problem with the retina and should be investigated immediately by your ophthalmologist, who may send you to a retinal specialist to check for retinal detachment.
Causes of Symptoms
Floaters are usually caused by the shrinking of the vitreous gel, which is found in the center of the eye and gives the eye its shape. The vitreous is attached to the retina, which lines the back of the eye. As you age, the center of the vitreous liquefies and the vitreous begins to shrink. When this happens, small pieces of gel break off and float around in the liquefied part of the vitreous. What you see is not the floater itself, but the shadow of the floater as it passes in front of the retina.
Floaters can indicate a posterior vitreous detachment, or PVD, which means that part of the vitreous has detached from the retina as it shrinks. PVDs should be checked by an ophthalmologist regularly to make sure the vitreous isn't pulling on the retina as it shrinks. When the vitreous shrinks, but remains attached to the retina, it pulls the retina off the wall of the eye, creating a retinal tear or retinal detachment, which can cause severe vision loss if not promptly treated.
Treatment of Symptoms
Floaters don't need treatment unless they indicate another underlying problem, such as a retinal tear or detachment. Tears and detachments need laser or surgical repair to re-attach the part of the retinal that's pulled away. If floaters are numerous and really disturbing, the vitreous can be removed and replaced by a saline solution in a process known as a vitrectomy. This may not completely eliminate all floaters, warns the Mayo Clinic.
