Dr. Adams says the power of the lens implanted is determined by the shape and length of your eye, using specialized equations. “The lens implant has a power of prescription like glasses,” he says. “We determine that using the shape of your cornea, how much focusing power it has, and the distance from where the lens is going to sit relative to your macula.” Once your eye is completely healed, you will likely need a new prescription for glasses or contact lenses for your best vision. “Cataract surgery improves vision loss related to the cloudy lens, like putting a clearer lens on a camera. Cataract surgery, or a new lens, does not correct vision loss from damage to the sensor or wires in the camera, like macular degeneration or damage to the nerves inside the eye, Dr. Adams explained.” Remember sudden loss of vision is not cataract and often is an emergency. If you experience sudden loss of vision, contact your doctor immediately or go to the emergency room.