Floaters are small, semitransparent or cloudy specks or particles within the fluid inside the eye (called vitreous) that become noticeable when they move within the line of sight. The vitreous is a transparent gel that fills two-thirds to three-fourths of the volume of the adult eye. The vitreous is two to four times as viscous as water. It is thought of as a shock absorber for the delicate retina, which lines the back of the eye. In a young eye, the vitreous is firmly attached to the retina. Floaters are generally translucent specks of various shapes and sizes. They may also appear as threadlike strands or cobwebs within the eye. Since they are within the eye, they move as the eye moves and often seem to dart away when you try to look at them directly.
A partial vitreous- retinal detachment, as a result of degeneration of the vitreous fluid, is a common age-related event in half of all adults over age 50. Typically, vitreous degeneration is a benign event and 85% of the time there is no significant consequence. Age-related vitreous degeneration is the most common cause for the sudden onset of a single large floater. Floaters of this type will typically move out of sight with the passage of time. Flashes of light may also occur as the changing vitreous tugs on the sensitive retina. Any persistent flashes or increase in floaters can be a sign of retinal tear or detachment and warrant immediate evaluation by an optometrist.