The vitreous is a clear liquid that fills our eyes and gives them shape. When we are young, the vitreous has a thick, gelatinous consistency and is firmly attached to the retina. As we age, the vitreous thins and separates from the retina. Although this usually results in nothing more than a few harmless floaters, tension from the detached vitreous can sometimes tear the retina.
If liquid seeps through the tear and collects behind the retina or between its nerve layers, the retinal tear can become a retinal detachment. Retinal detachment can cause significant, permanent vision loss and requires immediate medical treatment.
There are three kinds of retinal detachment. The most common form, described above, occurs when fluid leaks into the retina; people who are nearsighted or who have had an injury or eye surgery are most susceptible. Less frequently, friction between the retina and vitreous or scar tissue pulls the retina loose, something that occurs most often in patients with diabetes. Third, disease-related swelling or bleeding under the retina can push it away from the eye wall.
Signs of retinal tear or detachment include flashes of light, a group or web of floaters, wavy or watery vision, a sense that there is a veil or curtain obstructing vision, or a sudden drop in vision quality. If you experience any of these symptoms, call your doctor immediately. Early treatment is essential to preserve your vision.