Floaters

The small specks or “bugs” that many people see moving in their field of vision are called floaters. They are frequently visible when look at a plain background such as a blank wall or blue sky. Floaters were described a long time ago, in Roman times as flying flies (“muscae volitantes”).

Floaters are small clumps of gel that form in the vitreous, the clear jelly-like fluid that fills the inside cavity of the eye. Although they appear to be in front of the eye, they are actually floating in the fluid inside the eye and are seen as shadows by the retina (the light-sensing inner layer of the eye).

The appearance of floaters, whether in the form of little dots, circles, lines or cobwebs may cause much concern, especially if they develop suddenly. However, they usually are of little importance, representing an ageing process. The vitreous gel shrinks with time, pulls away from the retina and causes floaters. This is especially common in nearsighted people or after a cataract operation.

As the vitreous gel pulls away, the retina may be torn, sometimes causing a small amount of bleeding in the eye which may appear as a group of floaters. If this tear becomes a retinal detachment it can be serious. Uncommonly, floaters result from inflammation within the eye or from crystal-like deposits which form in the vitreous gel (asteroid hyalosis).

Without examination by an ophthalmologist, there is no way for a person to determine whether floaters are serious. Any sudden onset of many new floaters or flashes of light should be evaluated by your ophthalmologist.

Floaters may sometimes interfere with clear vision, often when reading, and can be quite annoying. If a floater appears directly in your line of vision, the best thing to do is to move your eye around, which will cause the inside fluid to swirl and allow the floater to move out of the way. We are most accustomed to moving our eyes left and right, but looking up and down will cause different currents within the eye and may be more effective in getting the floaters out of the way.

The vitreous gel which fills the inside of the eye sometimes pulls or tugs on the retina. This pulling causes the appearance of flashing lights or lightning streaks,though there is no flashing light actually present. This same sensation sometimes occurs when one is hit in the eye and see “stars”.

When vitreous separation pulls the gel away from the retina, flashes of light may appear on and off for several weeks. This commonly happens as we grow older and is usually no cause for alarm. On rare occasions, light flashes are associated with large number of new floaters and even a blacking out of part of the field of vision. When this occurs, immediate examination within a few days by your ophthalmologist is important to determine if a retinal tear or retinal detachment has developed. If your sight disappears you must be examined immediately.

flashes of light, which appear as jagged line or “heat waves” lasting 10-20 minutes and are present in both eyes, are likely to be a migraine caused by spasm of blood vessels in the brain. If a headache follows, it is called a migraine headache. However, these jagged lines or “heat waves” can occur commonly without a subsequent headache. In this case, the light flashes are referred to as ophthalmic migraine, or migraine without headache.

Floaters or flashes of light do not usually indicate any serious eye problem. If a large number develop or if they seem to be much worse over a period of time, an examination by your ophthalmologist is recommended. The examination will involve a careful observation of the retina and vitreous gel. Specialist training and experience is required to perform this examination properly.