A cataract is a clouding of the lens of the eye that interferes with vision.
The natural lens of the eye is located behind the pupil and iris. Normally, it is clear and transmits light easily. The lens refracts, or bends, light rays coming into the eye. This causes the light rays to focus on the retina. Any clouding of the lens will interfere with normal vision.
The human lens is a living tissue and puts down layers of growth like the rings seen in a log cut in cross section. As the rings of growth accumulate, the lens becomes harder to focus in middle age (this leads to the need for reading glasses.)
As the years go by, frank clouding occurs when proteins in the lens change and group together. These changes are part of normal aging and typically progress very slowly. Some cataracts occur in perfectly healthy adults in their 30s and 40s are may be rapidly progressive. They are not a sign of generalized disease. Rarely, cataracts may be congenital, that is, present at birth.
As a cataract develops, the person's vision changes slowly. Common symptoms include the following: cloudy or blurred visionfading of colorsa feeling of looking through a haze or fogglareincreased sensitivity to lightpoor night visionrainbows or halos around lights
As a cataract worsens, individuals may have difficulty reading. There may be frequent changes in eyeglass or contact lens prescriptions.
Most cataracts develop during the normal course of aging. Proteins in the lens change and group together. Over time, the lens becomes firmer or more opaque. Infants and children can have cataracts, although this is rare. Following are some of the other causes of cataracts: chromosomal abnormalities, such as Down syndromediabetes and other metabolic disordersexposure to high-voltage electricity, including lightningheredityinfections before birth, such as measlesinjury to the eyeliving at high altitudes with exposure to sunlightmedications, including steroidspremature birthradiation treatment around the eye
Cataracts are part of the normal aging process The following recommendations are part of a healthy lifestyle which may delay the progression of cataracts: Avoid excessive alcohol, illegal drugs, and smoking.Wear a hat with a long brim or glasses that block ultraviolet light.
Diagnosis of cataracts begins with a medical history and physical exam. The healthcare professional can use a slit lamp to examine the eye. When the pupil is dilated, the examiner can see any cloudiness in the lens.
If left untreated, cataracts become gradually more opaque with time.
Cataracts are not contagious and pose no risk to others.
When cataracts first start to form, vision may occasionally be improved for a time before surgery. Some steps to improve vision at that stage include: stronger prescription eyeglassesbrighter lighting
When vision interferes with everyday activities, the healthcare professional may recommend surgery for cataract removal. The surgeon removes the cloudy lens. It is then replaced with an artificial lens called an intraocular implant. The surgery is usually done in a same-day surgery setting in less than 30 minutes.
Some people have increased light sensitivity after cataract removal. Others need to use their glasses more. Glaucoma or retinal detachment are rare complications of cataract surgery. Most patients may resume normal activities, except swimming, within one or two days after surgery. Surgery can be complicated by bleeding, infection, or reactions to anesthesia.
Surgical treatment for cataracts usually results in excellent vision. If the individual has other eye problems, these may need further treatment. Underlying corneal or retinal disease may prevent persons from seeing 20/20 after the operation.
Any new or worsening symptoms should be reported to the healthcare professional.