FLOATERS

By middle age, most people see small, dark shapes that appear to float in their field of vision. The shapes may be round, oval or very irregular. These are called floaters.

They are particles in the vitreous body, a jelly-like substance that fills the inside of the eye. The vitreous body is attached to the retina, the layer of light-sensitive tissue at the back of the eye. Floaters appear in the field of vision because they cast shadows on the retina.

Floaters are usually more obvious against a clear background such as a bright sky or a sheet of white paper.

They move quickly with eye movement and drift away when eye movement stops.
Some floaters can interfere severely with vision, while others are barely noticeable. Although annoying, floaters are usually harmless, and come and go over the years.

Flashes

Small flashes of light may be seen with or without the appearance of floaters. Flashes are usually caused by the vitreous body tugging on the retina.

This tugging occurs when the vitreous body shrinks as a normal part of the ageing process. Flashes may last for a few seconds or several minutes, and can occur off and on for weeks or months. They are usually seen at night or in poor lighting.

(Migraine headache can cause the perception of similar light flashes appearing as jagged lines blocking an area of vision. These migraine flashes are unrelated to the vitreous body and its  attachment to the retina.)

Some images and information provided courtesy of RANZCO and Mi-tec Medical Publishing. The complete RANZCO patient education pamphlet is available from your ophthalmologist.