They are particularly noticeable when one is looking at a light-coloured background such as a clear sky or a white wall. Floaters come in many sizes and numbers, and they appear to move when the eye looks in different directions. The inside of the eye is filled with a clear, gel-like substance called the vitreous. The vitreous helps maintain the shape of the eye and allows light to pass through to the retina. The retina is a thin, light-sensitive tissue that covers the inside back portion of the eye and works like the film in a camera.
Floaters are small clumps of gel that form in the vitreous.
Although they appear to be in front of the eye, they are actually floating in the vitreous and are seen as shadows by the retina. The appearance of floaters may cause concern, especially if they develop suddenly. However, they are usually of little importance. As people get older, the vitreous shrinks and often separates from the retina. As the vitreous detaches, it causes floaters.