The back cavity of the eye is filled with a jelly-like material called the vitreous.
Patients often describe the floater as appearing as a fly or spider in their vision.
With rare exceptions, a posterior vitreous detachment is not a dangerous condition and does not lead to further damage to the eye. Occasionally, however, when the vitreous separates from the back wall of the eye, it can pull and cause a tear in the retina. A tear in the retina may allow fluid to seep under the retina and cause a retinal detachment, a serious eye condition. Flashes may occur as a result of adhesion of the vitreous to the retina which stimulates the retina, causing the perception of sparks of light when no lights actually exist. Diagnosis of posterior vitreous detachment is accomplished by an eye examination with dilation of the pupil.