Question on: SS3 Physics - Light Waves II

The human eye is a complex optical instrument that uses the cornea and lens to focus light onto the retina, where photoreceptor cells convert the light into electrical signals that are transmitted to the brain. Common vision disorders include myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia. Treatments for these disorders include eyeglasses and contact lenses, and surgical procedures.