The retina is a layer of nerves at the back of your eye that senses light and then sends images to your brain. Your eye is like a camera. The lens in front of your eye focuses the light to the retina. In a way, you can think of the retina as film that covers the back of the camera like wallpaper. It needs to stay flattened against the back of the eye to work properly.
Your eye is filled with a clear gel called vitreous. This gel is usually clear and smooth. As you age, however, it’s possible for the vitreous to pull away from its attachment to the retina at the back of the eye. It’s also possible for pockets or gaps to develop in the gel. Most of the time, this happens without causing any problems.
Sometimes, though, the vitreous can pull and tear the retina in one or even multiple places. The vitreous can then pass through the tear, causing the retina to peel off the back wall of the eye just like wallpaper would. A detached retina can occur at any age, but it is more common at middle age or later.