A normal human eye is made of many parts that function together to create clear vision. The lens in a normal eye is a clear part that helps to focus light, or an image, on the retina, which is the light-sensitive tissue found at the back of the eye.
In a properly functioning eye, light passes through the clear lens and on to the retina. At the retina, light is translated into nerve signals that are then sent to the brain. For the retina to receive a sharp image the lens must be clear. If the lens becomes clouded by a cataract, the image will appear blurred. Eye care associates are trained to detect and correct these types of eye trouble.