Cataracts

A cataract is a clouding of the lens of the eye, which is typically clear. For people who have cataracts, seeing through cloudy lenses is often like looking through a frosty or fogged-up window. Clouded vision caused by cataracts can make it hard to read, drive a car at night or see the expression on a friend's face.

Most cataracts develop slowly and don't disturb eyesight early on. But with time, cataracts will eventually affect vision.

At first, stronger lighting and eyeglasses can help deal with cataracts. But if impaired vision affects usual activities, cataract surgery might be needed. Cataract surgery is generally a safe, effective procedure.

Symptoms of cataracts include:

• Clouded, blurred or dim vision.
• Need for brighter light for reading and other activities.
• Trouble seeing in sunlight or bright lights.
• Trouble seeing at night.
• Halos or starbursts around lights at night.
• Frequent changes in eyeglass or contact lens prescription.
• Fading or yellowing of colors.
• Double vision in one eye.

At first, the cloudiness in vision caused by a cataract may affect only a small part of the eye's lens. Vision loss may be slight at first. As the cataract progresses, it clouds more of the lens. More clouding changes the light passing through the lens. This may lead to symptoms being more noticeable and symptoms that affect everyday activities.

When to see a doctor

Make an appointment for an eye exam if you notice any changes in your vision. If you develop sudden vision changes, such as double vision or flashes of light, sudden eye pain, or a sudden headache, see a member of your healthcare team right away.

Most cataracts develop when aging or injury changes the tissue that makes up the lens of the eye. Proteins and fibers in the lens begin to break down. This causes vision to become hazy or cloudy.

Some conditions passed down from parents or caused by gene variants can increase the risk of cataracts. Cataracts also can be caused by other eye conditions, past eye surgery or medical conditions such as diabetes. Long-term use of steroid medicines also may cause cataracts to develop.

How a cataract forms

The lens sits behind the colored part of your eye, called the iris. The lens focuses light that passes into your eye. This light is focused on the back part of the eye, called the retina.

As you age, the lenses in your eyes become less flexible, thicker and less clear. Aging and some medical conditions can cause proteins and fibers within a lens to break down and clump together. This is what causes the clouding in a lens.

As the cataract grows, the clouding becomes worse. A cataract scatters and blocks the light as it passes through the lens. This prevents a clearly defined image from reaching your retina. As a result, your vision becomes blurred.

Cataracts usually happen in both eyes, but not always at the same rate. The cataract in one eye may be worse than the other. This causes a difference in vision between eyes.

Types of cataracts

Cataracts can happen in different parts of the lens. The location of the cataract determines how vision is affected.

• Nuclear cataract. The nucleus is the center of the lens. A cataract usually causes far away objects to look blurry. Near vision generally stays the same at first and may improve for a while. The lens slowly turns more yellow or brown and makes your vision worse. This cataract can make it hard to see colors or tell some colors apart.
• Cortical cataract. The cortex is a layer of the lens that wraps all around the nucleus. A cortical cataract usually grows slowly. People with cortical cataracts often experience a glare that makes it hard to see in bright lighting. With an advanced cortical cataract, the lens appears completely white.
• Posterior subcapsular cataract. A posterior subcapsular cataract is in the back outer layer of the lens. This cataract usually affects near and distance vision and can make it hard to see in bright lights. This type of cataract tends to grow faster than others.
• Childhood cataracts. Some people are born with cataracts or develop them later in childhood. These cataracts may be caused by a genetic disorder, an infection during pregnancy, childhood disease or trauma.

Cataracts most often affects older adults. Other factors that increase your risk of cataracts include:

• Diabetes.
• Exposure to sunlight.
• Smoking and other tobacco use.
• Obesity.
• Family history of cataracts.
• Previous eye injury, disease or surgery.
• Prolonged use of corticosteroid medicines.
• Drinking excessive amounts of alcohol.

No studies have proved how to prevent or slow the growth of cataracts. But healthcare professionals think several strategies may be helpful, including:

• Regular eye exams. Eye exams can help detect cataracts and other eye conditions at their earliest stages. Ask your healthcare team how often you should have an eye examination.
• Do not smoke. Ask a member of your healthcare team how to stop smoking. Medicines, counseling and other strategies are available to help you.
• Manage other health problems. Follow your treatment plan if you have diabetes or other medical conditions that can increase your risk of cataracts.
• Choose a healthy diet that includes plenty of fruits and vegetables. Adding fruits and vegetables to your diet ensures that you're getting vitamins, nutrients and antioxidants that can improve eye health and may reduce the risk of cataracts.
• Wear sunglasses. Ultraviolet light from the sun increases the risk of cataracts. When you're outdoors, wear sunglasses that block ultraviolet B rays.
• Reduce alcohol use. Drinking too much alcohol can increase the risk of cataracts.

Your eye doctor will ask questions about your health and medical history and do a thorough examination of your eyes. These tests can show whether you have vision loss and what may be causing it. Tests may include:

• Vision test. A vision test, also called a visual acuity test, uses eye charts to measure how well you can read a series of letters. One eye is tested at a time, while the other eye is covered. Your eye doctor determines how well you can see and what kind of corrective lenses you may need.
• Microscopic exam. Your eye doctor may use a specialized microscope to look at the outer eye and structures inside the eye. This exam is often done with a device called a slit lamp. This uses bright light and a microscope to see precise details of structures or irregularities in your eye. Your eye doctor will look at the condition of the nerves at the back of the eye. This exam also can show if you have a cataract in a lens. With this exam, you may have eye drops to enlarge your pupils.
• Intraocular pressure test. This measures the pressure inside your eye. There are multiple devices available to do this.
• Questionnaire. You may fill out a form that asks you questions about how your vision affects your ability to do daily activities. If you have a cataract, this information helps in developing a treatment plan.

When your prescription glasses or contacts can't clear your vision, the only effective treatment for cataracts is surgery.

When to consider cataract surgery

Talk with your eye doctor about whether surgery is right for you. Most eye doctors suggest considering cataract surgery when your cataracts begin to affect your quality of life. This may include your ability to perform daily activities, such as reading or driving at night.

For most people, there is no rush to remove cataracts because they usually don't harm the eyes. But cataracts can worsen faster in people with certain conditions. These include diabetes, high blood pressure or obesity.

Waiting to do cataract surgery typically won't affect how well your vision recovers. Take time to consider the benefits and risks of cataract surgery with your healthcare team.

If you choose not to have cataract surgery now, your eye doctor may recommend periodic follow-up exams to see if your cataracts are getting worse. How often you'll see your eye doctor depends on your situation.

What happens during cataract surgery

Cataract surgery involves removing the clouded lens and replacing it with a clear artificial lens. The artificial lens, called an intraocular lens, is put in the same place as your natural lens. It remains a permanent part of your eye.

In rare situations, artificial lenses can't be used. In these situations, once the cataract is removed, vision may be corrected with eyeglasses or contact lenses.

Cataract surgery is typically done on an outpatient basis. This means you won't need to stay in a hospital after the surgery. During surgery, your eye doctor uses a medicine to numb the area around your eye. You usually stay awake during the procedure.

Cataract surgery is generally safe. However, it carries a risk of infection and bleeding. Cataract surgery also increases the risk of the retina being pulled out of place. This is called retinal detachment.

After the procedure, you may be sore for a few days. Healing usually happens within a few weeks.

If you need cataract surgery in both eyes, most often your eye doctor will schedule surgery to remove the cataract in the second eye after you've healed from the first surgery.

To deal with symptoms of cataracts until you decide to have surgery, try to:

• Make sure your prescription for your eyeglasses or contact lenses is up to date.
• Use a magnifying glass to read if you need more help reading.
• Improve the lighting in your home with more or brighter lamps.
• Wear sunglasses or a broad-brimmed hat to reduce glare during the day.
• Limit driving at night.

Make an appointment with your usual eye care professional if you notice changes in your vision. If you have a cataract, you may be referred to an eye specialist who can perform cataract surgery.

There's often a lot to talk about. It's a good idea to be well prepared for your appointment so that you can make the most of your time. Here's some information to help you get ready.

What you can do

• List any symptoms you're experiencing, including any that may not seem related to the reason you scheduled the appointment.
• Make a list of all medicines, vitamins or supplements that you're taking, the doses, and the reason for taking each one.
• Take a family member or friend along. Sometimes it can be hard to absorb all the information provided during an appointment. Someone who comes with you may remember something that you missed or forgot.
• List questions to ask your healthcare team.

For cataracts, some basic questions to ask include:

• Are cataracts causing my vision problems?
• What kinds of tests do I need?
• Will cataract surgery correct my vision problems?
• What are the potential risks of cataract surgery? Are there risks in waiting to do surgery?
• What will cataract surgery cost, and will my insurance cover it?
• How much time will I need to recover from cataract surgery?
• Will any usual activities be restricted after cataract surgery? For how long?
• After cataract surgery, how long should I wait before getting new glasses?
• If I use Medicare, will it cover the cost of cataract surgery? Does Medicare cover the cost of new glasses after surgery?
• If I don't want surgery right now, what else can I do to help with my vision changes?
• How will I know if my cataracts are getting worse?
• I have these other health conditions. How can I best manage these conditions together?
• Are there any brochures or other printed material that I can take with me? What websites do you recommend?

In addition to the questions that you've prepared, don't hesitate to ask questions at any time if you don't understand something.

What to expect from your doctor

Your healthcare team is likely to ask you a number of questions. Being ready to answer them may allow more time later to cover other points you want to talk about. You may be asked:

• When did you begin having symptoms?
• Do you have your symptoms all the time or do they come and go?
• Is it hard for you to see in bright light?
• Is it hard for you to see at night?
• Have your symptoms gotten worse?
• Does your vision affect your ability to drive?
• Do you find it hard to read?
• Does your vision affect your ability to do your job?
• Have you ever had an eye injury or eye surgery?
• Have you ever been diagnosed with an eye disease?
• Have you ever received radiation therapy to your head or neck?