Floaters

Fragments perceived to be floating in the field of vision. Floaters move rapidly with eye movement but drift slightly when the eyes are still. They do not usually affect vision. Most floaters are shadows cast on the retina by microscopic structures in the vitreous humour (the jelly-like substance behind the lens). The sudden appearance of a cloud of dark floaters, especially when accompanied by light flashes, suggests retinal tear or retinal detachment. A large red floater that obscures vision is usually due to a vitreous haemorrhage.