The small specks, ‘"bugs" or clouds that you may sometimes see moving in your field of vision are called floaters. They are frequently visible when looking at a plain background, such as a blank wall or blue sky. These visual phenomena have been described for centuries; the ancient Romans called them muscae voliantes or "flying flies" since they can appear like small flies moving around in the air. Floaters, are actually tiny clumps of jell or cellular debris within the vitreous: the clear jelly-like fluid that fills the inside cavity of the eye. Although these objects appear to be in front of the eye, they are actually floating in the fluid inside the eye and cast their shadows on the retina (the light-sensing inner layer of the eye).

Although the floaters appear to be in front of the eye, they are actually floating in the vitreous fluid inside the eye. Moving your eyes back and forth and up and down creates currents within the vitreous capable of moving the floater outside your direct line of vision.

The vitreous jell degenerates in middle age, often forming microscopic clumps or strands within the eye. Vitreous shrinkage or condensation is called posterior vitreous detachment, and is a common cause of floaters. It also occurs frequently in near sighted people or in those who have undergone cataract operations or YAG Laser surgery. Occasionally, floaters result from inflammation within the eye or from crystal-like deposits which form in the vitreous jell. The appearance of floaters, whether in the form of little dots, circles, lines, clouds or cobwebs may be alarming, especially if they develop suddenly. However, they are usually nothing to be concerned about, and simply result from the normal aging process.

As shown in the illustration, the vitreous covers the retinal surface. Occasionally the retina is torn when degenerating vitreous jell pulls away. This causes a small amount of bleeding in the eye which may appear as a group of new floaters. A torn retina can be serious if it develops into a retinal detachment. Any sudden onset of many new floaters or flashes of light should be promptly evaluated by your medical eye doctor. Additional symptoms, especially loss of peripheral or side vision, require repeat ophthalmic examination.

Floaters may interfere with clear vision, often when reading and can be quite annoying. Although there is no treatment or cure for most floaters, they usually diminish by themselves over time. You can take simple measures to temporarily move them from your sight. If a floater appears directly in your line of vision, try moving your eye around. The inside fluid may swirl and allow the floater to move out of the way. We are most accustomed to moving our eyes side to side, 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.

When the vitreous jell which fills the inside of the eye rubs or pulls on the retina, it sometimes produces the illusion of flashing rights or lightning streaks. You may have experienced this same sensation if you have ever been hit in the eye and seen stars. The flashes of light may appear off and on for several weeks or months, This commonly occurs as we grow older and is usually not cause for worry. On rare occasions, however, light flashes accompany a large number of new floaters and even a partial loss or shadowing of side vision. When this happens, prompt examination by a medical eye doctor is important to determine if a torn retina or retinal detachment has occurred. Flashes of light which appear as jagged lines or "heat waves" often lasting 10 - 20 minutes and present in both eyes, are likely to be migraine caused by a spasm of blood vessels in the brain. If a headache follows, it is called a migraine headache. However, these jagged lines or "heat waves" commonly occur without a subsequent headache. In this case, the light flashes are referred to as ophthalmic migraine, or migraine without headache.

As with floaters, if you experience the abrupt onset of many light flashes you should be examined by an ophthalmologist. The examination will involve a careful observation of the retina and vitreous jell after your pupils have been dilated with eye drops. Medical training and experience is required to perform this examination properly.

An ophthalmologist is the medical doctor (MBBS, FRANZCO) who is educated, trained and licensed to provide total care of the eyes, including evaluation of floaters and flashes. Total eye care includes performing comprehensive medical eye examinations, prescribing corrective lenses, diagnosing diseases and disorders of the eye, and using the appropriate medical and surgical procedures necessary for their treatment.