The eyeball is a hollow organ connected to the brain by the optic nerve. On entering the eye, the optic nerve spreads out in a thin layer of nervous tissue-the retina-and covers the inside of the eye like wallpaper.
The inside of the eye is filled with a transparent, jelly-like material called the vitreous. Disorders of the vitreous body are related to the normal aging process in which the jelly begins to liquefy, resulting in a mixture of liquid and gel. Where the solid and liquid meet in the eye, debris tends to gather, resulting in "floaters" or small cobwebs that we see when we move our eyes.
When the jelly-like vitreous begins to liquefy and collapse, it may tug on the nerve-tissue lining of the eye (the retina) and produce flashes of light. This symptom should be carefully evaluated. The collapsing vitreous may be attached to the retina in spots and may cause localized tears in the retina. These tears open holes in the wallpaper-like retina; the liquid portion of the vitreous is sometimes able to seep through the hole and peel the retina away from its blood supply in the wall of the eye. This results in a retinal detachment with potentially severe loss of vision.
Floaters and flashing lights in the vision should be evaluated by an eyecare specialist to ensure that they do not represent a dangerous condition. If abnormal holes are found in the retina and are caught early enough, a laser can normally be used to seal them and decrease the danger of retinal detachment. If a detachment has actually started, surgery may be required to remedy the problem