Cataract
Cataracts are the leading cause of vision loss, according to the centers for Disease Control and Prevention. They typically develop after age 55, but younger patients can be affected as well, including some infants at birth. About 18% of Americans aged 40 or older (more than 25 million people) have a cataract in one or both eyes.
Cataracts progress in stages, but the development of the condition depends on age, exposure to UV experienced over a lifetime, genetic factors and some lifestyle factors, such as smoking, high alcohol consumption or nutritional deficiencies.
They form in the center of the lens, known as the nucleus. As they get worse, your reading vision may actually get better at first. It’s called second sight, but it’s short-lived.
Types of Cataract
Nuclear cataracts:
A nuclear cataract may at first cause more near-sightedness or even a temporary improvement in your reading vision. But with time, the lens gradually turns more densely yellow and further clouds your vision.
As the cataract slowly progresses, the lens may even turn brown. Advanced yellowing or browning of the lens can lead to difficulty distinguishing between shades of color.
Cortical cataracts:
A cortical cataract begins as whitish, wedge-shaped opacities or streaks on the outer edge of the lens cortex. As it slowly progresses, the streaks extend to the center and interfere with light passing through the center of the lens.
Posterior subcapsular cataracts:
A posterior subcapsular cataract starts as a small, opaque area that usually forms near the back of the lens, right in the path of light. A posterior subcapsular cataract often interferes with your reading vision, reduces your vision in bright light, and causes glare or halos around lights at night. These types of cataracts tend to progress faster than other types do.
Congenital cataracts:
Some people are born with cataracts or develop them during childhood. These cataracts may be genetic or associated with an intrauterine infection or trauma.
These cataracts also may be due to certain conditions, such as myotonic dystrophy, galactosemia, neurofibromatosis type 2 or rubella. Congenital cataracts don’t always affect vision, but if they do they’re usually removed soon after detection.
Risk factors
Factors that increase your risk of cataracts include:
Is there a Prevention?
No studies have proved how to prevent cataracts or slow the progression of cataracts. Have regular eye examinations. Eye examinations can help detect cataracts and other eye problems at their earliest stages. Ask your doctor how often you should have an eye examination.
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