A cataract is when your eye's natural lens becomes cloudy. Proteins in your lens break down and cause things to look blurry, hazy or less colorful.
In this article:
Inside our eyes, we have a natural lens. The lens bends (refracts) light rays that come into the eye to help us see. The lens should be clear, like the top lens in the illustration.
Vision Problems with Cataracts
If you have a cataract, your lens has become cloudy, like the bottom lens in the illustration. It is like looking through a foggy or dusty car windshield. Things look blurry, hazy or less colorful with a cataract.
The top lens is a clear, natural lens. The bottom lens shows clouding by cataract.
Video: What Are Cataracts?
Here are some vision changes you may notice if you have a cataract:
If you notice any of these cataract symptoms, notify your ophthalmologist.
Cataracts can make images appear dull or yellow.
Blurry or dim vision is a symptom of cataracts.
Cataracts can cause distortion or ghost images.
See a simulation of what vision with cataract looks like.
What Causes Cataracts?
Aging is the most common cause. This is due to normal eye changes that happen starting around age 40. That is when normal proteins in the lens start to break down. This is what causes the lens to get cloudy. People over age 60 usually start to have some clouding of their lenses. However, vision problems may not happen until years later.
Other reasons you may get cataracts include:
Most age-related cataracts develop gradually. Other cataracts can develop more quickly, such as those in younger people or those in people with diabetes. Doctors cannot predict how quickly a person’s cataract will develop.
You may be able to slow down your development of cataracts.
Protecting your eyes from sunlight is the best way to do this. Wear sunglasses that screen out the sun’s ultraviolet (UV) light rays. You may also wear regular eyeglasses that have a clear, anti-UV coating. Talk with your eye doctor to learn more.
Your ophthalmologist will examine and test your eyes to make a cataract diagnosis. This comprehensive eye exam will include dilation. This means eye drops will widen your pupils.
Your ophthalmologist will examine your cornea, iris, lens and the other areas at the front of the eye. The special slit-lamp microscope makes it easier to spot abnormalities.
When your eye is dilated, the pupils are wide open so the doctor can more clearly see the back of the eye. Using the slit lamp, an ophthalmoscope or both, the doctor looks for signs of cataract. Your ophthalmologist will also look for glaucoma, and examine the retina and optic nerve.
Refraction and visual acuity test
This test assesses the sharpness and clarity of your vision. Each eye is tested individually for the ability to see letters of varying sizes.
Once I have a cataract diagnosis, what should I do?
- Have an eye exam every year if you're older than 65, or every two years if younger.
- Protect your eyes from UV light by wearing sunglasses that block at least 99 percent UV and a hat.
- If you smoke, quit. Smoking is a key risk factor for cataracts.
- Use brighter lights for reading and other activities. A magnifying glass may be useful, too.
- Limit driving at night once night vision, halos or glare become problems.
- Take care of any other health problems, especially diabetes.
- Get the right eyeglasses or contact lenses to correct your vision.
- When it becomes difficult to complete your regular activities, consider cataract surgery.
- Make an informed decision about cataract surgery. Have a discussion with your ophthalmologist about:
- the surgery,
- preparation for and recovery after surgery,
- benefits and possible complications of cataract surgery,
- cataract surgery costs,
- other questions you have.
Cataracts can be removed only with surgery.
If your cataract symptoms are not bothering you very much, you don’t have to remove a cataract. You might just need a new eyeglass prescription to help you see better. You should consider surgery when cataracts keep you from doing things you want or need to do.
How does cataract surgery work?
During cataract surgery, your eye surgeon will remove your eye’s cloudy natural lens. Then he or she will replace it with an artificial lens. This new lens is called an intraocular lens (or IOL). When you decide to have cataract surgery, your doctor will talk with you about IOLs and how they work.
People who have had cataract surgery may have their vision become hazy again years later. This is usually because the eye’s capsule has become cloudy. The capsule is the part of your eye that holds the IOL in place. Your ophthalmologist can use a laser to open the cloudy capsule and restore clear vision. This is called a capsulotomy.
Cataracts are a very common reason people lose vision, but they can be treated. You and your ophthalmologist should discuss your cataract symptoms. Together you can decide whether you are ready for cataract surgery.