260 Medical Terminology: Mastering the Basics Cataract A cataract (KĂT-ă-răct) is a clouding of the lens of the eye (Figure 6.5). The lens of the eye is normally clear. It functions like the lens of a camera, focusing light as it travels to the retina at the back of the eye. Normally, the shape of the lens is able to change, allowing the eye to focus on an object, whether it is close or far away. With age, the lens begins to break down and becomes cloudy. As a result, vision may become blurred. Refraction of light rays Refraction of light rays Refraction of light rays Focusing point on retina Focusing point in front of retina Focusing point behind retina A. Normal vision: Light rays focus on the retina. B. Myopia (nearsightedness): Light rays focus in front of the retina. C. Hyperopia (farsightedness): Light rays focus beyond the retina. Retina Light Light Light Figure 6.4 Myopia and hyperopia Alila Medical Media/Shutterstock.com Figure 6.5 A cataract is a clouding of the lens of the eye. Cataracts are typically associated with aging. Clear lens Normal Cataract Cloudy lens