The retina is a thin membrane of nerve tissue that lines the back of the eye. When part or all of the retina comes off (detaches from) the back of the eye, it is called retinal detachment .
The nerve cells in the retina normally detect light entering the eye and send signals to the brain about what the eye sees. But when the retina detaches, it no longer works correctly. It can cause blurred and lost vision. Retinal detachment requires immediate medical care. If done soon enough, surgery can save lost vision.
Retinal detachment usually happens because there's a tear (hole) in the retina. The most common cause of a tear is posterior vitreous detachment (PVD). Vitreous gel fluid flows through the tear, pools beneath the retina, and lifts the retina off the back of the eye.
Retinal detachment can also happen without a retinal tear. Scar tissue buildup in the eye may pull on the retina. This is called traction. Or, fluid can build up under the retina for a different reason than a retinal tear.
Some of the reasons that make a person more likely to get a retinal detachment are an eye or head injury, nearsightedness, eye disease, and diabetes.
Unfortunately, most cases of retinal detachment cannot be prevented. But seeing your eye doctor regularly, wearing protective helmets and eyeglasses, and treating diabetes may help protect your vision.
Many people see floaters and flashes of light before they have symptoms of retinal detachment. Floaters are spots, specks, and lines that float through your field of vision. Flashes are brief sparkles or lightning streaks that are most easily seen when your eyes are closed. They often appear at the edges of your visual field. Floaters and flashes do not always mean that you will have a retinal detachment. But they may be a warning sign, so it is best to be checked by a doctor right away.
Sometimes a retinal detachment happens without warning. The first sign of detachment may be a shadow across part of your vision that does not go away. Or you may have new and sudden loss of side (peripheral) vision that gets worse over time.