what is a retinal detachment.?

The U.K.'s Edinburgh Evening News (9/29) reported that "a detached retina is a rare, but serious, condition which can cause blindness if it is not treated quickly. It affects around one in 10,000 people, usually those who are middle-aged and very" nearsighted, but, in certain cases, "it is seen in younger people who have a retinal weakness. Cataract surgery, ocular tumors, and diabetic eye disease can also be causes." Detachment can happen when there is "a tear in the retina, allowing fluids to leak underneath and leading to the retina peeling off its choroid, which contains the blood vessels which nourish" it. The "most common symptom" of a detached retina "is a shadow or curtain spreading across the eye. Dark spots called floaters are also common, but none of these symptoms are painful." The Evening News urged readers "with these symptoms" to "have them checked out as quickly as possible," because "the sooner the retina is reattached, the better the chances of saving vision." The article also featured the experiences of a young woman who had suffered two retinal detachments, one of which cost the vision in her right eye.