The retina is the light-sensitive tissue at the back of the eye that sends images to the brain. Normally, the retina lies against the back of the eye where blood vessels furnish it with oxygen and nutrients. Tears in the retina may impair vision and lead to a detached retina. A detached retina occurs when the retina pulls away from the inside wall of the eye. When this happens, vision becomes blurred, shaded or distorted.