The vitreous space is located posteriorly between the lens of the eye and the retina. It is filled with a material called vitreous which is similar to clear gel. As we age, the normal jelly-like consistency of the vitreous begins to liquefy. The vitreous may contract and pull away from its natural attachments on the inside surface of the eye. When it pulls free, it is often accompanied by light flashes and the appearance of a new black spot or floater.
This is not dangerous, but it can be accompanied by more serious eye conditions such as retinal tears and vitreous haemorrhage. These occur when the strong attachments of the vitreous to the retina do not separate properly, tearing the retina or retinal blood vessels. This often leads to new floaters and persistent light flashes. It is suggested that anyone with symptoms of a vitreous detachment have an eye examination to make certain that a more serious problem is not present.
Normal floaters are not dangerous and are caused by tiny specks of tissue inside the vitreous. When light hits these pieces of tissue, it creates shadows on the retina that appear to float across your field of vision.
It may appear that these specks are on the front surface of your eye, but they are actually inside. Except in rare circumstances, floaters are no cause for alarm and no treatment is necessary. However, a sudden increase in new floaters may indicate a problem, and an eye examination is recommended if this occurs.
Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.