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When Things Are Getting Cloudy: Understanding Cataracts

The ability to see is another of the everyday wonders that we may too often take for granted

The entire visual world reaches us through two very small openings: the pupils at the front of our eyes. Light coming in at the pupil passes through a lens, which focuses it on the retina, a light-sensitive tissue at the back of the eye. The various colors and patterns of light falling on the retina are then transmitted by nerve signals to the brain, which sorts through all the incoming visual data and helps us identify and recognize the objects we're looking at.

The lens is a clear, bulging disk about ten millimeters across and shaped like the lens of a camera, and it plays a critical role in vision. To do its work well — that is, to focus a sharp and accurate image on the retina — the lens needs to be clear, just like the lens in a camera or in a pair of glasses.

As we age, our vision can change, and not usually for the better. If you've noticed your vision becoming cloudy or blurry, or otherwise less sharp than it was when you were younger, the culprit may be a cataract.

What Is a Cataract?

The eye's lens is made up mostly of water and protein. When we're young and our vision is sharp, the proteins in the lens are arranged in an optimal way that keeps the lens clear. As we age, some of the protein can begin to clump together and cloud over a small part of the lens. That clouding is called a cataract. 

Cataracts grow slowly, and eventually the lens takes on a yellowish/brown color. If they keep growing, cataracts can make it more difficult to see clearly, and we can end up feeling as though we're looking through a dirty window onto a world that is blurrier, dimmer and less colorful than it used to be. There may come a time when cataracts are significantly interfering with your day-to-day activities, such as reading, watching TV, or driving.

If you've noticed your vision becoming cloudy or blurry, or otherwise less sharp than it was when you were younger, the culprit may be a cataract.

Are You At Risk For Developing a Cataract?

As we get older, our risk of developing cataracts increases. As a common part of the aging process, the proteins in the lens start to break down around the age of 40. The cataracts that form during middle age are usually small and don't have much effect on your vision. It's very common for people over 60 to have some clouding of their vision, but more significant vision problems may not show up until years later. By the age of 80, more than half of Americans either have a cataract or have had their cataracts fixed surgically.

Beyond simply getting older, other risk factors for cataracts include:

• Specific medical problems, like diabetes
• An eye injury or eye surgery
• Radiation treatments on your upper body
• A family history of cataracts
• Environmental factors such as spending a lot of time in the sun without protective eyewear
• Lifestyle choices such as drinking and smoking
• Certain nutritional deficiencies

What Are the Symptoms Of Cataracts?

Keep in mind that vision difficulties are not necessarily a sign that you have cataracts. There could be other eye problems involved. Ask your doctor about getting a complete eye exam if you notice any of the following symptoms:

• Blurry or clouded vision
• Poor night vision
• Colors appearing faded
• Glare or a "halo" effect around lamps, headlights, or other light sources
• Sunlight appearing too bright
• Double vision or multiple images in one eye
• Requiring frequent changes in your eyeglasses or contact lens prescription

Your eye doctor will likely give you a comprehensive eye exam, which will include tests of your visual acuity (how well you see at different distances), a dilated eye exam (in which your pupils will be widened and the doctor will look inside to view the structures of your eye), and tonometry (a test measuring the pressure inside your eye).

How Are Cataracts Treated?

If your cataracts aren't bothering you too much — if they're not interfering with your daily activities or posing a safety risk — you may be helped by remedies such as getting new glasses, installing brighter lighting, using magnifying lenses, or wearing anti-glare sunglasses.

But if those steps aren't getting the job done, and if your vision loss is impairing your ability to drive, read, or watch TV, the next step is likely to be surgery. In cataract surgery, the cloudy lens is removed and replaced with an artificial lens called an intraocular lens, or IOL. The IOL replaces the focusing power of your natural lens.

Monofocal IOLs are the most common option, used for decades, and covered by most insurance companies.

In many cases – but not in all cases – the other options may correct vision so that you no longer need glasses or contact lenses. At the same time, these options are more expensive and are less likely to be covered by insurance. They include:

• Multifocal IOLs.  These feature multiple corrective zones built into the lens, like bifocal or trifocal eyeglasses, for near and far vision.
• Extended depth-of-focus (EDOF) IOLs. These are made with one corrective zone that is stretched to support distance and intermediate vision.
• Accommodative lenses. These use the eye’s natural movements to change focus for all distances.
• Toric lenses. These are made to correct for astigmatism.

Source: National Eye Institute; American Academy of Ophthalmology