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Cataract - adult

Lens opacity; Age-related cataract

A cataract is a clouding of the lens of the eye.

Causes

The lens of the eye is normally clear. It acts like the lens on a camera, focusing light as it passes to the back of the eye.

Until a person is around age 45, the shape of the lens is able to change. This allows the lens to focus on an object, whether it is close or far away.

As a person ages, proteins in the lens begin to break down. As a result, the lens becomes cloudy. What the eye sees may appear blurry. This condition is known as a cataract.

Factors that may speed cataract formation are:

  • Diabetes
  • Eye inflammation
  • Eye injury
  • Family history of cataracts
  • Long-term use of corticosteroids (taken by mouth) or certain other medicines
  • Radiation exposure
  • Smoking
  • Surgery for another eye problem
  • Too much exposure to ultraviolet light (sunlight)

In many cases, the cause of cataract is unknown.

Symptoms

Cataracts develop slowly and painlessly. Vision in the affected eye slowly gets worse.

  • Mild clouding of the lens often occurs after age 60. But it may not cause any vision problems.
  • By age 75, most people have cataracts that affect their vision.

Problems with seeing may include:

  • Being sensitive to glare
  • Cloudy, fuzzy, foggy, or filmy vision
  • Difficulty seeing at night or in dim light
  • Double vision
  • Loss of color intensity
  • Problems seeing shapes against a background or the difference between shades of colors
  • Seeing halos around lights
  • Frequent changes in eyeglass prescriptions

Cataracts lead to decreased vision, even in daylight. Most people with cataracts have similar changes in both eyes, though one eye may be worse than the other. Often there are only mild vision changes.

Exams and Tests

A standard eye exam and slit-lamp examination are used to diagnose cataracts. Other tests are rarely needed, except to rule out other causes of poor vision.

Treatment

For early cataract, the eye doctor may recommend the following:

  • Change in eyeglass prescription
  • Better lighting
  • Magnifying lenses
  • Sunglasses

As vision gets worse, you may need to make changes around the home to avoid falls and injuries.

The only treatment for a cataract is surgery to remove it. If a cataract is not making it hard for you to see, surgery is usually not necessary. Cataracts usually do not harm the eye, so you can have surgery when you and your eye doctor decide it is right for you. Surgery is usually recommended when you cannot do normal activities such as driving, reading, or looking at computer or video screens, even with glasses.

Some people may have other eye problems, such as diabetic retinopathy, that cannot be treated without first having cataract surgery. 

Outlook (Prognosis)

Vision may not improve to 20/20 after cataract surgery if other eye diseases, such as macular degeneration, are present. The eye doctor (ophthalmologist) can often determine this in advance.

Possible Complications

Early diagnosis and treatment are key to preventing permanent vision problems.

Although rare, a cataract that goes on to an advanced stage (called a hypermature cataract) can begin to leak into other parts of the eye. This may cause a painful form of glaucoma and inflammation inside the eye.

When to Contact a Medical Professional

Call for an appointment with your eye care professional if you have:

  • Decreased night vision
  • Problems with glare
  • Vision loss

Prevention

The best prevention involves controlling diseases that increase the risk of a cataract. Avoiding exposure to things that promote cataract formation can also help. For example, if you smoke, now is the time to quit. Also, when outdoors, wear sunglasses to protect your eyes from harmful UV rays.

References

American Academy of Ophthalmology Preferred Practice Patterns Cataract and Anterior Segment Panel, Hoskins Center for Quality Eye Care. Cataract/anterior segment summary benchmark - 2016. Updated October 2016. www.aao.org/summary-benchmark-detail/cataract-anterior-segment-summary-benchmark-2016. Accessed October 21, 2016.

Tipperman R. Cataracts. In: Gault JA, Vander JF, eds. Ophthalmology Secrets in Color. 4th ed. Philadelphia, PA: Elsevier; 2015:chap 21.

Wevill M. Epidemiology, pathophysiology, causes, morphology, and visual effects of cataract. In: Yanoff M, Duker JS, eds. Ophthalmology. 4th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 5.17.

    • Cataracts

      Cataracts

      Animation

    •  

      Cataracts - Animation

      Many of us take for granted that, when we open our eyes each morning, we'll have a pretty clear view of the world. But as we get older, we often have trouble seeing as well as we used to. By the time you're 75, there's a pretty good chance you'll develop cataracts. Having cataracts is kind of like seeing through a blurry, hazy cloud. Let's talk today about cataracts. Normally the lens of your eye is clear. It works much like the lens on a camera. When light hits the lens, it focuses an image on the back of your eye. Until a person is around age 45, the shape of the lens is able to change. This allows the lens to focus on an object, whether it is close or far away. As we age, proteins in the lens begin to break down and the lens then becomes cloudy. A cataract is like having a cloud pass over your lens. Only, that cloud never moves on. Cataracts are common after the age of 60. But some people are more likely than others to get them than others; including those with diabetes, and people who smoke or who had surgery for another eye problem. You're also more likely to get cataracts if you don't wear sunglasses outside and your eyes are exposed to a lot of damaging ultraviolet light from the sun. People with a family history of cataracts are also at greater risk. And, sometimes, doctors can't even find any cause for them. When you have a cataract, the world looks blurry or fuzzy. You have trouble making out shapes, and colors aren't as rich as usual. You may not notice much of a change in your vision at first. For minor vision loss, you can compensate by changing your eyeglass prescription and using brighter lights to read or work. But eventually, the cataract will block more and more of your sight. And then you'll need surgery to have it removed and replaced your lens with a nice new artificial one. Often cataract surgery can restore 20/20 vision, especially in people who don't have other eye diseases. You may be able to live with your cataracts; at least, for a while. Even if your vision isn't bothering you however, keep in touch with your eye doctor. Letting a cataract go for too long can lead to other problems, including a certain type of glaucoma. If you can't see as well as you used to, get an eye exam. To protect your eyes, treat diseases like diabetes, which can cause cataracts. And always wear a good pair of sunglasses outside to shield your eyes from the ultraviolet damage from the sun.

    • Cataract

      Animation

    •  

      Cataract - Animation

      Cataracts may develop with advancing age or in response to diseases such as diabetes. A cataract appears as a cloudy area in the lens.

    • Eye

      Eye - illustration

      The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.

      Eye

      illustration

    • Slit-lamp exam

      Slit-lamp exam - illustration

      A slit-lamp, which is a specialized magnifying microscope, is used to examine the structures of the eye (including the cornea, iris, vitreous, and retina). The slit-lamp is used to examine, treat (with a laser), and photograph (with a camera) the eye.

      Slit-lamp exam

      illustration

    • Cataract - close-up of the eye

      Cataract - close-up of the eye - illustration

      This photograph shows a cloudy white lens (cataract) as seen through the pupil. Cataracts are a leading cause of decreased vision in older adults, but children may have congenital cataracts. With surgery, the cataract can be removed, a new lens implanted, and the person can usually return home the same day.

      Cataract - close-up of the eye

      illustration

    • Cataract surgery - series

      Cataract surgery - series

      Presentation

    • Cataracts

      Animation

    •  

      Cataracts - Animation

      Many of us take for granted that, when we open our eyes each morning, we'll have a pretty clear view of the world. But as we get older, we often have trouble seeing as well as we used to. By the time you're 75, there's a pretty good chance you'll develop cataracts. Having cataracts is kind of like seeing through a blurry, hazy cloud. Let's talk today about cataracts. Normally the lens of your eye is clear. It works much like the lens on a camera. When light hits the lens, it focuses an image on the back of your eye. Until a person is around age 45, the shape of the lens is able to change. This allows the lens to focus on an object, whether it is close or far away. As we age, proteins in the lens begin to break down and the lens then becomes cloudy. A cataract is like having a cloud pass over your lens. Only, that cloud never moves on. Cataracts are common after the age of 60. But some people are more likely than others to get them than others; including those with diabetes, and people who smoke or who had surgery for another eye problem. You're also more likely to get cataracts if you don't wear sunglasses outside and your eyes are exposed to a lot of damaging ultraviolet light from the sun. People with a family history of cataracts are also at greater risk. And, sometimes, doctors can't even find any cause for them. When you have a cataract, the world looks blurry or fuzzy. You have trouble making out shapes, and colors aren't as rich as usual. You may not notice much of a change in your vision at first. For minor vision loss, you can compensate by changing your eyeglass prescription and using brighter lights to read or work. But eventually, the cataract will block more and more of your sight. And then you'll need surgery to have it removed and replaced your lens with a nice new artificial one. Often cataract surgery can restore 20/20 vision, especially in people who don't have other eye diseases. You may be able to live with your cataracts; at least, for a while. Even if your vision isn't bothering you however, keep in touch with your eye doctor. Letting a cataract go for too long can lead to other problems, including a certain type of glaucoma. If you can't see as well as you used to, get an eye exam. To protect your eyes, treat diseases like diabetes, which can cause cataracts. And always wear a good pair of sunglasses outside to shield your eyes from the ultraviolet damage from the sun.

    • Cataract

      Animation

    •  

      Cataract - Animation

      Cataracts may develop with advancing age or in response to diseases such as diabetes. A cataract appears as a cloudy area in the lens.

    • Eye

      Eye - illustration

      The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.

      Eye

      illustration

    • Slit-lamp exam

      Slit-lamp exam - illustration

      A slit-lamp, which is a specialized magnifying microscope, is used to examine the structures of the eye (including the cornea, iris, vitreous, and retina). The slit-lamp is used to examine, treat (with a laser), and photograph (with a camera) the eye.

      Slit-lamp exam

      illustration

    • Cataract - close-up of the eye

      Cataract - close-up of the eye - illustration

      This photograph shows a cloudy white lens (cataract) as seen through the pupil. Cataracts are a leading cause of decreased vision in older adults, but children may have congenital cataracts. With surgery, the cataract can be removed, a new lens implanted, and the person can usually return home the same day.

      Cataract - close-up of the eye

      illustration

    • Cataract surgery - series

      Presentation

    Review Date: 8/11/2015

    Reviewed By: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Editorial update 10/21/2016.

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