Cataract

A cataract is a clouding of the eye’s lens that affects your ability to see clearly. While most cataracts develop slowly with age, they can eventually make everyday activities like reading, driving at night, or recognizing faces increasingly difficult. The good news is that cataract surgery is one of the safest and most common operations performed today, offering a reliable way to restore clear vision.

Table of contents

• What is a Cataract?
• Understanding the Eye’s Lens
• Types of Cataracts
• Signs and Symptoms
• What Causes Cataracts?
• Who Is at Risk?
• How Cataracts Are Diagnosed
• Treatment Options
• Prevention and Protection
• Living with Cataracts

What is a Cataract?

A cataract is a clouding of the lens of the eye, which is normally clear. The lens is a transparent structure located behind the colored part of your eye (the iris) that helps focus light onto the retina, the light-sensitive tissue at the back of your eye.^[1]

For people who have cataracts, seeing through cloudy lenses is like looking through a frosty or fogged-up window. You may feel as if you’re looking at the world through a dirty window.^[1][3] Clouded vision caused by cataracts can make it more difficult to read, drive a car at night, or see the expression on a friend’s face.^[1]

Cataracts are very common as you get older. In fact, more than half of all Americans age 80 or older either have cataracts or have had surgery to get rid of cataracts.^[2] By age 80, most people either have cataracts or have had cataract surgery, and cataract surgery is one of the most common operations in the United States.^[2]

• Eye lens
• Iris
• Retina

Understanding the Eye’s Lens

The lens is a clear, flexible structure made mostly of proteins called crystallins. It works much like a camera lens, focusing light onto the retina at the back of the eye, where an image is recorded. The lens also adjusts the eye’s focus, letting you see things clearly both up close and far away.^[7]

Your lens is made up of several layers. The nucleus is in the center of your lens, like the core of an apple. The cortex is the layer that surrounds the nucleus, similar to the fruit you eat that surrounds the core. The lens capsule is the thin membrane covering the cortex, like a close-fitting skin that covers and protects the lens.^[3]

The lens is composed of an evenly arranged layer of water and proteins. Cataracts form when these proteins begin to clump together.^[13] As you get older, the proteins in your lens break down, forming cloudy patches that affect your vision.^[3]

Types of Cataracts

There are many types of cataracts. Most cataracts are related to age—they happen because of normal changes in your eyes as you get older. But you can get cataracts for other reasons, like after an eye injury or after surgery for another eye problem (like glaucoma).^[2]

The three most common types of age-related cataracts are classified based on where they form in your lens:^[3]

• Nuclear sclerotic cataract, which forms in the nucleus (the center of the lens)
• Cortical cataract, which forms in the cortex (the layer surrounding the nucleus)
• Posterior subcapsular cataract, which forms in the posterior cortex (the back part of the lens, closest to your retina). This type forms at the outer edge of the cortex, just beneath the lens capsule

Often, people have more than one type at the same time. That’s because it’s common for cloudy patches to form in multiple areas of your lens.^[3]

Other cataract types include:^[3]

• Pediatric cataracts affect babies and children. Babies may be born with cataracts (congenital), or the cataracts may form sometime after birth. Pediatric cataracts typically run in families, but they can also happen due to eye injuries or other eye conditions. Babies and children with pediatric cataracts need prompt treatment to prevent problems like amblyopia (lazy eye)
• Traumatic cataracts form when something injures your eye. Treatment for this type is more complicated because structures around the lens may also need repair
• Secondary cataracts are cloudy patches that form on your lens capsule, or the membrane that covers your lens. Another term for this condition is posterior capsular opacification. It’s a common but easily treatable complication of cataract surgery

You can get cataracts in one eye or both eyes—but they can’t spread from one eye to the other.^[2]

Signs and Symptoms

At first, you may not notice that you have a cataract. But over time, cataracts can make your vision blurry, hazy, or less colorful. You may have trouble reading or doing other everyday activities.^[2]

Most cataracts develop slowly and don’t disturb eyesight early on. But with time, cataracts will eventually affect vision.^[1] You might not have any symptoms at first, when cataracts are mild. But as they grow, cataracts can cause changes in your vision.^[2]

Symptoms of cataracts include:^[1][2]

• Clouded, blurred, or dim vision
• Trouble seeing at night
• Sensitivity to light and glare
• Need for brighter light for reading and other activities
• Seeing “halos” around lights
• Frequent changes in eyeglass or contact lens prescription
• Fading or yellowing of colors
• Double vision in one eye (this sometimes goes away as the cataract gets bigger)

At first, the cloudiness in your vision caused by a cataract may affect only a small part of the eye’s lens. You may not notice any vision loss. As the cataract grows larger, it clouds more of your lens.^[1]

The symptoms can significantly impact your quality of life, making routine tasks increasingly challenging. This gradual loss of clear vision can impede everyday activities like reading, driving, recognizing faces, and navigating in low-light conditions.^[20] When cataracts are advanced, the pupil of your eye may appear grey or white.^[6]

What Causes Cataracts?

Most cataracts happen because of normal changes in your eyes as you get older. When you’re young, the lens in your eye is clear. Around age 40, the proteins in the lens of your eye start to break down and clump together. This clump makes a cloudy area on your lens—known as a cataract. Over time, the cataract gets worse and makes more of your lens cloudy.^[2]

The proteins in your eye’s lens start to break down around age 40. But you typically won’t notice symptoms until age 60 or later. Certain medical conditions, like diabetes, may cause you to have symptoms sooner.^[3]

Cataract formation is primarily driven by oxidative stress, which damages lens proteins, leading to their aggregation and the accumulation of clumps of protein or yellow-brown pigment in the lens. This reduces the transmission of light to the retina at the back of the eye, impairing vision. Additionally, alterations in the lens’s metabolic processes, including imbalances in calcium and other ions, contribute to cataract development.^[5]

Cataracts are often caused by aging. Other causes include traumatic eye injury, surgery to treat other eye problems, diabetes, cancer treatment radiation, medications, smoking or alcohol use, or UV light exposure. Sometimes, cataracts are present at birth.^[13]

Who Is at Risk?

Your risk for cataracts goes up as you get older. If you are aged over 40 years, you are more likely to develop cataracts than a younger person. Half of all Australians over 50 years are affected by cataracts. By the age of 70 or 80 years, almost everyone develops cataracts.^[6]

You’re also at higher risk if you:^[2][6]

• Have certain health problems, like diabetes
• Smoke
• Drink too much alcohol
• Have a family history of cataracts
• Have had an eye injury, eye surgery, or radiation treatment on your upper body
• Have spent a lot of time in the sun
• Take steroids—medicines used to treat some health problems, like arthritis or allergies
• Used corticosteroid medicines for long periods
• Had some types of eye operations (for example, a vitrectomy)
• Had radiation treatment, such as for cancer

In addition to these, poor nutrition, obesity, chronic kidney disease, and autoimmune diseases have been recognized in various studies as contributing to the development of cataracts.^[5]

In rare cases, babies are born with a cataract (congenital cataract).^[6]

How Cataracts Are Diagnosed

To determine whether you have a cataract, your eye doctor will review your medical history and symptoms. They also will perform an eye exam. Your doctor may do several tests, including:^[8]

• Vision test. A vision test, also called a visual acuity test, uses an eye chart to measure how well you can read a series of letters. One eye is tested at a time, while the other eye is covered. A chart or a viewing device with letters that get smaller is used. With this, your eye doctor determines if you have 20/20 vision or if you have trouble seeing
• Eye structure exam. An eye structure exam, also called a slit lamp, allows your eye doctor to see the structures at the front of your eye up close. It’s called a slit lamp because it uses an intense line of light, a slit, to light up the structures in your eye. The slit allows your doctor to view these structures in small sections. This makes it easier to find anything that may be wrong
• Retinal exam. A retinal exam looks at the back of your eyes, called the retina. To prepare for a retinal exam, your eye doctor puts drops in your eyes to open your pupils wide, called dilation. This makes it easier to see the retina. Using a slit lamp or a special device called an ophthalmoscope, your eye doctor can examine your lens for signs of a cataract
• Fluid pressure test. This test, also called applanation tonometry, measures fluid pressure in your eye. There are multiple different devices available to do this

Diagnosis is typically through an eye examination, with ophthalmoscopy and slit-lamp examination being the most effective methods. During ophthalmoscopy, the pupil is dilated, and the red reflex is examined for any opacities in the lens. Slit-lamp examination provides further detail.^[5]

If you are experiencing any symptoms or have changes in your vision, you should see an optometrist as soon as you can. If they are concerned about cataracts, your optometrist or doctor may refer you to an ophthalmologist (a specialist eye doctor). They may arrange further investigations and possibly surgery.^[6]

Treatment Options

The only effective and permanent treatment for cataracts is surgery. This is one of the safest and most commonly performed surgeries in the world, with over 3 million procedures performed annually in the U.S. alone.^[10] No matter what type of cataract you have, you’ll need surgery to treat it.^[2]

However, surgery is not always immediately necessary. At first, stronger lighting and eyeglasses can help deal with cataracts. But if impaired vision affects usual activities, cataract surgery might be needed.^[1]

Currently, there is no effective way to treat cataracts without surgery. However, you may not need to have surgery immediately. A healthcare professional might recommend delaying surgery unless your symptoms are interfering with your daily activities, such as going to work and driving.^[12]

When your prescription glasses can’t clear your vision, the only effective treatment for cataracts is surgery. Most eye doctors suggest considering cataract surgery when your cataracts begin to affect your quality of life or interfere with your ability to perform normal daily activities.^[8][19]

Managing Cataracts Before Surgery

Instead of immediate surgery, your doctor may suggest ways to manage your symptoms while the condition is in its early stages, including:^[12]

• Getting a new prescription for your eyeglasses or contact lenses
• Having annual eye exams to monitor the progression of the condition
• Using brighter lights to see better
• Wearing anti-glare sunglasses

In the early stages of cataract formation, you might notice a slight decline in your vision, but not so much that it affects your day-to-day activities. When that’s the case, the following tips can help:^[17]

• See your eye doctor for a new eyeglass or contact lens prescription
• Put brighter lightbulbs in the lamps around your home, especially the ones you use to read or do other close work
• Reduce glare by positioning lights directly behind you, pointed on the task (such as on the book you’re reading)
• Use magnifying lenses to read or work
• Place contrasting colors—such as a dark blanket on a light chair—around your home to help you see better

Cataract Surgery

Fortunately, cataract surgery is generally a safe, effective procedure.^[1] The good news is that surgery can get rid of cataracts. Cataract surgery is safe and corrects vision problems caused by cataracts.^[2]

Before cataract surgery, your ophthalmologist will numb your eyes with medicated eyedrops and administer mild sedation. Your clinician will use tiny incisions to remove the lens that is affected by cataract and replace it with an unclouded, artificial lens. The surgery is painless.^[3] The entire procedure usually takes less than 30 minutes in the operating room, and recovery is often quick with only mild post-surgical symptoms.^[10]

During cataract surgery, your surgeon will replace your natural cloudy lens with a clear artificial lens known as an intraocular lens (IOL). There are several types of IOLs to choose from, each offering different visual benefits:^[10]

• Monofocal IOLs provide clear vision at one distance (usually viewing beyond arm’s reach). Most will still require glasses, usually for up close vision/reading and may require bifocals depending on your level of astigmatism
• Toric IOLs provide clear vision at one distance and are customized for patients with irregularly shaped corneas that cause higher levels of astigmatism. Most will still require glasses, usually for up close vision/reading
• Multifocal IOLs are designed to give vision at multiple distances, providing clear vision at both distance and near, eliminating the need for glasses for distance viewing and reading

After cataract surgery, you are unlikely to experience any significant discomfort. Cataract surgery patients typically enjoy excellent outcomes.^[3] More than 95% of people who undergo cataract surgery end up with better vision.^[17]

Typically, people have surgery in the eye with the denser cataract first. If the other eye has only a minimal cataract, a second eye surgery many not be needed for years. However, most people with age-related cataracts have similar disease in both eyes, and the second eye is usually done a few weeks after the first one, once it’s had a chance to heal.^[17]

Prevention and Protection

You can take steps to protect your eyes from cataracts:^[2]

• Protect your eyes from the sun. Wear sunglasses and a hat with a brim to block the sun. You can wear sunglasses to protect your eyes from damage by ultraviolet light^[6]
• Protect your eyes from injury. While doing activities like using power tools or playing certain sports, wear protective eyewear to protect your eyes from getting hurt
• Maintain a healthy lifestyle. Fresh produce contains nutrients that are vital to maintaining healthy eyes. This cannot cure or stop cataract development, but some studies have shown that a healthier lifestyle may slow progression^[16]
• Don’t smoke. If you need help quitting, talk with your doctor
• Limit alcohol. Drinking too much alcohol can increase your risk

If you are aged over 40 years, see your optometrist for regular eye tests. It is important to always stay on top of your eye exams but this is especially important when managing a condition like cataracts. Your ophthalmologist will be able to track any changes to your vision and help determine the best time for surgery.^[6][16]

Living with Cataracts

Living with cataracts impacts nearly every area of your life. Routine activities like driving, reading a book, and going to the grocery store are impacted and become more challenging. Adjusting to these problems can be tough, but there is a way. Although managing your cataract symptoms can be hard, it is far from impossible. Many people learn how to manage their cataracts and live a full life.^[16]

Living with cataracts does not mean that you can’t have an active and rewarding life. It simply means you need to take precautions and take care of your health.^[16]

Here are some tips for managing your cataract symptoms:^[16][20]

• Take extra care when driving. If your cataract symptoms are severe, they will impact your ability to drive. Nighttime driving can be especially challenging since the light from streetlamps can cause a glare, making it hard to see. You should check with your doctor to ensure that it is safe for you to continue driving. You may need to develop a plan for safe transportation in the future
• Elicit help from family and friends. You shouldn’t feel like you have to bear this burden alone. Often, family members and friends would be happy to help out with household tasks. This will be especially helpful in the beginning as you are first learning how to manage your blurry vision
• Stay up-to-date on your comprehensive eye exams. Your ophthalmologist will be able to track any changes to your vision and help determine the best time for surgery. They will also be able to recommend lifestyle changes that may slow the progression of cataracts
• Maintain a healthy lifestyle. Fresh produce contains nutrients that are vital to maintaining healthy eyes. Plus, maintaining a healthy lifestyle will help the rest of your body stay in top shape as well
• Optimize lighting. Enhance the lighting in your home and workspace. Use bright, non-glare light bulbs and install additional lamps where needed. Proper lighting can reduce eye strain and make tasks easier to manage^[20]
• Reduce glare. Wear sunglasses with UV protection and a wide-brimmed hat when outdoors to minimize glare from the sun. Indoors, use anti-glare screens for your devices and adjust window coverings to control sunlight^[20]
• Improve contrast. Increase the contrast in your home by using colored tape on steps, handrails, and door edges. High-contrast items, like white dishes on a dark tablecloth, can make everyday tasks easier^[20]
• Create a safe home environment. Remove tripping hazards like loose rugs and ensure that furniture is arranged safely^[20]
• Explore all treatment options. There are temporary treatment options available for cataract patients (such as glasses and other visual aids) but ultimately, cataract surgery is the only cure. You should continue to discuss this option with your doctor so you can decide when cataract surgery is right for you^[16]

These measures help many people safely delay cataract surgery for years. Some end up never needing surgery. But people who rely on their eyes for detailed work, such as architects, dentists, and jewelers, may need surgery sooner than others.^[17]

For the first few weeks after cataract surgery, it’s important to take certain precautions. During the first week, people should avoid lifting things heavier than 10 to 15 pounds. For the first two weeks, people shouldn’t wear eye makeup and should also avoid swimming, baths, and hot tubs. Vision may be blurry in the first few days after surgery, but gradually will improve. Most people remark that things appear brighter and clearer.^[17]