A cataract is a clouding of the normally clear lens of your eye. For people with cataracts, looking through a cloudy lens is like looking through a frosty or foggy window. Blurred vision caused by glaucoma can make it more difficult to read, drive a car (especially at night), or see expressions on a friend’s face.
Most cataracts develop slowly and do not impair your vision quickly. But over time, cataracts will eventually interfere with your vision.
First, strong light and glasses can help you deal with cataracts. But if poor vision interferes with your normal activities, you may need cataract surgery. Fortunately, cataract surgery is generally a safe, effective procedure.
Signs and symptoms of glaucoma include:
- Blurred, blurred or blurred vision
- Double vision in one eye
- Increasing difficulty with night vision
- Bright light needed for reading and other activities
- Sensitivity to light and glare
- Seeing “halos” around lights
- Frequent change in prescription for glasses or contact lenses
At first, blurring of your vision due to cataracts may affect only a small part of the lens of the eye and you may be unaware of any vision loss. As a cataract gets bigger, it becomes more cloudy on your lens and distorts the light passing through the lens. This can lead to more noticeable symptoms.
Most cataracts develop when aging or injury replaces the tissue that makes up the lens of your eye.
Certain inherited genetic disorders that cause other health problems can increase your risk of cataracts. Cataracts can also be caused by other eye conditions, previous eye surgery, or medical conditions such as diabetes. Long-term use of steroid drugs can also lead to cataracts.
How Cataracts Form
The lens, where the cataract occurs, is located at the back of the colored part (iris) of your eye. The lens focuses the light that goes into your eye, producing clear, sharp images on the retina – the light-sensitive membrane in the eye that acts like the film in a camera.
As you age, the lens of your eye becomes less flexible, less transparent, and thicker. Age-related and other medical conditions cause the tissue within the lens to break down and clump together, causing small areas within the lens to become cloudy.
As the cataract continues to develop, the cloud becomes thicker and covers a greater part of the lens. A cataract scatters and blocks light as it passes through the lens, thereby preventing a clearly defined image from reaching your retina. As a result, your vision becomes blurry.
Cataracts usually develop in both eyes, but not equally. A cataract in one eye may be more advanced than in the other eye, causing a difference in vision between the eyes.
Types of cataracts
Types of cataracts include:
Cataracts affecting the center of the lens (nuclear glaucoma). A nuclear glaucoma may at first cause more nearsightedness or even a temporary improvement in your reading vision. But over time, the lens gradually turns a more intense yellow and blurs your vision further.
As the cataract progresses slowly, the lens may also turn brown. Advanced yellowing or browning of the lens can make it difficult to distinguish between shades of color.
Cataracts that affect the edges of the lens (cortical cataract). A cortical cataract begins as white, wedge-shaped opacity or streaks on the outer edge of the lens cortex. As it progresses slowly, the streaks extend to the center and interfere with the light passing through the center of the lens.
Cataracts that affect the back of the lens (posterior subcapsular cataract). A posterior subcapsular cataract begins as a small, opaque area that forms in the path of light, usually behind the lens. A posterior subcapsular cataract often interferes with your reading vision, impairs your vision in bright light, and causes glare or halos around lights at night. This type of cataract progresses faster than other types.
You are born with glaucoma (congenital glaucoma). Some people are born with cataracts or develop them in childhood. These cataracts may be genetic, or may be associated with intrauterine infection or trauma.
These cataracts can also be caused by certain conditions, such as myotonic dystrophy, galactosemia, neurofibromatosis type 2 or rubella. Congenital cataracts do not always affect vision, but if they do occur they are usually removed soon after they are detected.
Cataracts Risk Factors
Factors that increase your risk of cataracts include:
- Growing old
- Excessive exposure to sunlight
- Long-term use of corticosteroid drugs
- Previous eye injury or inflammation
- High blood pressure
- Previous eye surgery
- Consuming too much alcohol
No studies have proven how to prevent cataracts or slow the progression of cataracts. But doctors think several strategies can be helpful, including:
- Get your eyes checked regularly. An eye exam can help detect cataracts and other eye problems early. Ask your doctor how often you should have an eye exam.
- Quit smoking. Ask your doctor for tips on how to stop smoking. Medicines, counseling, and other strategies are available to help you.
- Manage other health problems. If you have diabetes or other medical conditions that may increase your risk of glaucoma, follow your treatment plan.
- Choose a healthy diet that includes lots of fruits and vegetables. Including a variety of colorful fruits and vegetables in your diet ensures that you are getting many vitamins and nutrients. Fruits and vegetables contain many antioxidants, which help maintain the health of your eyes.
- Studies have not proven that antioxidants in pill form can prevent cataracts. But, a recent large population study showed that a healthy diet rich in vitamins and minerals was associated with a lower risk of developing cataracts. Fruits and vegetables have many proven health benefits and are a safe way to increase the amount of minerals and vitamins in your diet.
- Wear Sunglasses. Ultraviolet rays from the sun can contribute to the development of cataracts. Wear sunglasses that block ultraviolet B (UVB) rays when you are outside.
- Reduce alcohol consumption. Excessive alcohol consumption can increase the risk of cataracts.