A cataract is a clouding of the lens of the eye that can impair vision.
What Causes Cataracts?
The eye functions much like a camera. Light rays enter the eye, passing through the cornea, the aqueous humor, transparent fluid in the front of the eye, and then the pupil and into the lens. The lens bends the light rays to focus objects onto the retina lining the back of the eye. From there, the image passes through the retinal cells, into the optic nerve, and finally to the back of the brain which process the images.
Cataracts occur when there is a buildup of protein in the lens that makes it cloudy. This prevents light from passing clearly through the lens, causing some loss of vision. Since new lens cells form on the outside of the lens, all the older cells are compacted into the center of the lens resulting in the cataract.
Types of cataracts include:
Age-related cataracts - As the name suggests, this type of cataract develops as a result of aging.
Congenital cataracts - Babies are sometimes born with cataracts as a result of an infection, injury, or poor development before they were born, or they may develop during childhood.
Secondary cataracts - These develop as a result of other medical conditions, like diabetes, or exposure to toxic substances, certain drugs, ultraviolet light, or radiation.
Traumatic cataracts - These form after injury to the eye.
Other factors that can increase a person's risk of developing cataracts include cigarette smoke, air pollution, and heavy alcohol consumption
What are the Symptoms?
Cataracts usually form slowly and cause few symptoms until they noticeably block light. When symptoms are present, they can include:
- Vision that is cloudy, blurry, foggy, or filmy
- Progressive nearsightedness in older people
- Changes in the way you see color because the discolored lens acts as a filter.
- Problems driving at night
- Problems with glare during the day.
- Double vision
- Sudden changes in glasses prescription.
If your vision can be corrected to an acceptable level with a change in prescription eyeglasses, including bifocals or contacts, may be prescribed, eliminating the need for surgery at that time.
If your vision loss cannot be corrected with new glasses and cataracts interfere with your daily life, you may be a candidate for cataract surgery, which involves removing the clouded lens and replacing it with a clear, artificial one.
Because cataracts and other conditions such as glaucoma are common in older adults, it's important to have your eyes examined on a regular basis.
Be sure to ask your doctor if you have any risk factors or indications that cataracts or other conditions may affect your vision.