Black floaters are shadows caused by bits of a gelatinous material called vitreous humor that floats in the eye. Their appearances vary, from round spots and stringy shapes to fuzzier formations that look like cobwebs. Though they can occur at any age, they are most commonly experienced by the elderly. Most black floaters are benign and can be ignored, but a sudden increase in floaters can indicate a serious problem which requires immediate medical attention.
The gelatinous vitreous humor forms a ball inside the eye. It presses against the retina, providing support. As it ages, the center of the ball begins to liquefy, thus compromising both the structure of the ball and the security of the retina. As the vitreous humor weakens, it loses bits of fiber, which then cling together in small clusters that float in the eye until they dissolve. The shadows from these pieces form black floaters.
Black floaters are most visible in bright, direct light. Though they appear to be floating around the eye, the floaters are actually moving with the eye as it makes adjustments. The floaters can be a range of shades, from light gray to black.
If the number of black floaters suddenly increases or if they are accompanied by bright flashes of light and loss of vision, medical attention should be sought immediately. These symptoms may indicate that the degeneration of the vitreous humor has lead to an imbalance in the eye, most likely caused by retinal tears or detachment.
When the retina is detached, it is cut off from vital sources of blood, oxygen and nutrients that the eye needs to function correctly. Retinal tears often lead to detachment. It is imperative that a doctor address a retinal detachment quickly, before the lack of nourishment causes the eye to lose its ability to see.
Black floaters can also result from other medical conditions or even because of the shape of the eye. For example, people who are nearsighted have elongated eyes, which makes them more vulnerable to the pressure that can cause black floaters. Floaters can also appear due to diabetes or internal eye inflammation.
A more common and less serious condition that can be indicated by black floaters is posterior vitreous detachments (PVDs). This condition involves the retina becoming separated from the vitreous humor and does not require immediate attention. If PVD is not treated, however, it can eventually lead to retinal tears and detachment.
Most doctors recommend against surgery for black floaters that are solely annoying to the patient. There is a treatment option, however; the vitreous particles that cause the floaters can be removed from the eye and then replaced with saline.
