Prescription glasses work by bending light as it enters your eyes. This allows your eye to focus light on the correct spot on your retina. The retina is a layer of cells at the back of the eye that responds to light. This response is sent to the brain, which translates the cell's actions into a picture. In short, glasses work by bending light through curved lenses and, with the correct prescription, manipulating it to the correct location on the retina. The result is a crisp, clear image.