What causes it?
Floaters are condensations within the normally transparent vitreous gel.
The youthful vitreous is attached to the retina at several points by tiny fibrous bands. After age 60, or earlier if the patient is highly myopic or has had trauma, the vitreous develops a fluid pocket, or bursa. This fluid pocket makes the vitreous unstable and breaks the binding points. The vitreous then detaches from the retina and the binding points become suspended in front of the retina. There they cause shadows on the retina that look like veils , or specks.
To watch this sequence, click here.
In some cases, when the vitreous detaches, it tears a hole in the retina. Rarely, fluid from the vitreous can enter the hole and detach the retina. To watch this sequence, click here.
Other important causes of floaters: inflammation in the vitreous and bleeding from the retinal surface into the vitreous cavity.
What to do?
The sudden appearance of one or more floaters should suggest a disturbance in the vitreous or retina. Because of the concern for retinal tear and detachment, the patient should undergo prompt ophthalmologic examination.