Cataract diagram_1212 Slideshow
The lens is a clear part of the eye that helps to focus light, or an image, on the retina. The retina is the light-sensitive tissue at the back of the eye. In a normal eye, light passes through the transparent lens to the retina. The lens must be clear for the retina to receive a sharp image. If the lens is cloudy from a cataract, the image you see will be blurred.
This close-up of the eye in a 68-year-old female patient shows a dense cataract.
Obstructed vision from cataract_1212 Slideshow
Cataracts cause sight to become blurred and yellowed, and if left untreated will obscure the vision completely. In addition to primary cataracts that occur with old age, there are four other types.
Seconday Cataract_1212 Slideshows
Secondary cataracts form after surgery for other eye problems, such as glaucoma (pictured), or in people who have other health problems, like diabetes. Cataracts are sometimes linked to steroid use.
Traumatic cataract_1212 Slideshow
Traumatic cataracts can develop after an eye injury, sometimes years later.
Congenital cataract_1212 Slideshow
Some babies are born with cataracts or develop them in childhood, often in both eyes. Known as congenital cataracts, they may be so small that they do not affect vision. If they do, the lenses may need to be removed. This photo shows the distorted pupil of a 12-year-old girl after surgical treatment.
Radiation cataract_1212 Slideshow
Radiation cataract results from damaged cells covering the posterior surface of the lens. Symptoms can appear as early as one or two years following high-dose exposure and many years after exposure to lower doses.
There are two types of surgery to treat cataracts. The most commonly used technique today is phacoemulsification, which consists of making a small incision on the side of the cornea and inserting a tiny probe into the eye. This device emits ultrasound waves that soften and break up the lens so that it can be removed by suction.
Extracapsular surgery _1212 Slideshow
Extracapsular surgery consists of making a longer incision on the side of the cornea and removing the cloudy core of the lens in one piece. The rest of the lens is removed by suction.
A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging, with more than half of all Americans expected to either have a cataract or have had surgery for one by age 80 years.