Cataracts: Symptoms, Causes, Treatment & Prevention

This guide explains the causes and the risk. A cataract is clouding of the eye’s normally clear lens ². Lens or capsule opacification can obscure light passing through the lens to the retina ⁴. Cloudiness blocks light from reaching the back of the eye, making it harder to see clearly ².

A cataract scatters and blocks light before a clearly defined image can reach the retina ⁷. The retina is the back part of the eye where the lens normally focuses incoming light ⁷. When a clear image cannot reach the retina, the person's resulting vision becomes blurred as a result ⁷. As a cataract grows, its clouding can worsen and cover more of the affected eye's lens ⁶.

A cataract may occur in either eye or in both eyes ³. A cataract can affect one eye without affecting the other ². A cataract does not spread from one eye to the other ². Most cataracts form with age as lens proteins clump and block more sight ².

Most cataracts come with normal aging and are very common in older adults ². Age-related cataracts can occur in people during their 40s and 50s ³. Cataracts can affect babies and adults, but they most often affect older people ⁴. Some babies are born with cataracts or develop them during childhood, often in both eyes ³.

You need not be a senior citizen to get an age-related cataract ³. Cataracts most often affect older adults, but people can be born with them or develop them in childhood ⁷. Babies can be born with cataracts or develop them during childhood, often in both eyes ³. Back-layer cataracts are more common in younger people and grow fairly fast ¹.

Nuclear cataracts grow slowly and sometimes barely change sight, harming distance more than near ¹. Cortical cataracts grow slowly and often cause glare that hinders sight in bright light ⁷. Back-layer cataracts grow faster than other types and harm near and far sight ⁷. Back-layer cataracts grow faster than nuclear and cortical cataracts, which grow slowly ^1,7.

Cataracts can form after an eye injury or surgery for glaucoma or another condition ². Most cataracts come with age; eye injury or past surgery can also cause them ⁶. Smoking may increase cataract risk, and stopping smoking could lower that risk ¹. Diabetes, steroid medicines, smoking, or extensive sun exposure can raise cataract risk ².

Americans age 80 or older: more than half have cataracts or had cataract surgery ⁶. Several strategies may be helpful, according to healthcare professionals ⁷. No studies have proved how to prevent or slow the growth of cataracts ⁷. Regular eye exams are among strategies healthcare professionals think may be helpful ⁷.

Wear sunglasses and a hat with a brim to block the sun ⁶. Wear sunglasses and a wide-brimmed hat to block UV sunlight and help delay cataracts ². Eye injuries can cause cataracts, and power tools or certain sports may accidentally injure eyes ^2,6. While using power tools or playing certain sports, wear protective eyewear against eye injuries ⁶.

Quitting smoking may lower cataract risk because smoking may raise it ¹. Certain health problems, including diabetes, are associated with higher cataract risk; discuss concerns with your doctor ⁶. Quitting smoking and choosing fruits, vegetables, leafy greens, nuts, and whole grains may help protect your eyes ⁶.

This guide explains the symptoms and the vision changes. Mild cataracts may cause no symptoms; as they grow, vision may become cloudy, blurry, or faded ⁶. Cataracts tend to gradually reduce sight but cause no pain, burning, or similar symptoms ¹. Clouding, faded colors, bright glare, halos, poor night-sight, double vision, prescription changes are common ².

Cataracts can hinder reading, driving, watching TV, and other daily tasks ². Talk with your provider about cataract-like symptoms because other eye problems can cause the same changes ². Regular eye exams matter because slow-growing cataracts may go unnoticed at first ². See a healthcare team member right away if double vision, flashes, eye pain, or headache starts suddenly ⁷.

Cataracts can make vision increasingly cloudy or blurry, but they do not cause pain or burning ¹. Cloudy vision may feel like looking through fog, making fine details harder to see clearly ¹. Colors may lose contrast and look dull or faded as cataract-related vision changes progress ¹. Glare can make sunlight, headlights, or lamps seem too bright for a person with cataracts ².

Cataracts may produce halos, which appear as rings of light around lamps, headlights, or sunlight ^1,2. Poor night sight can make driving after dark especially hard for people with cataracts ^1,3. Frequent eyeglass or contact lens prescription changes are a known cataract symptom ³. Cataracts often cause blur, clouding, faded colors, glare, halos, and poor night sight ².

If you have any of these symptoms, check with your eye care professional ³. Early cataracts may go unseen; later, worsening cataracts can blur or dim sight ². As cataracts worsen, more lens clouding makes symptoms more noticeable in daily life ⁷. Worsening cataracts can hinder reading, night driving, and other daily tasks ^6,7.

A cataract can cause double vision or multiple images in one eye, and this symptom may clear ³. Double vision may fade as the cataract grows, so this symptom can change ³. A nuclear cataract may leave near vision unchanged at first and may improve it for a while ⁷. For some, cataracts change focus, clearing close objects while worsening far sight ¹.

People who were farsighted may see better without glasses for a short while as their lens changes ¹. This near vision gain doesn't last long; cataracts gradually cloud and blur sight ¹. Cataracts can weaken contrast, make colors dull or faded, and hide fine details ¹. Over time, weaker contrasts and poor night vision can make driving harder, particularly at night ^1,3.

Cataracts can harm depth sense, making it hard to judge how far objects are ¹. Reduced depth perception makes distances harder to judge, while poor vision raises the risk of falling ¹. Poor vision from cataracts increases the risk of falling and getting hurt ¹.

This guide cannot tell you the cause of the blurry vision. Cataracts usually develop slowly; seek care right away for sudden vision changes, sudden eye pain, or sudden headache ^2,7. For sudden vision loss, see a member of your healthcare team right away ⁷. For sudden flashes of light, see a member of your healthcare team right away ⁷.

For sudden eye pain, see a member of your healthcare team right away ⁷. For a sudden headache, see a member of your healthcare team right away ⁷. You should get any new symptoms diagnosed as soon as possible to rule out more serious issues ⁹.

Speak with a clinician about cloudy vision that is new. Cataracts usually grow slowly, blurring or dimming sight before they interfere with your daily activities ². Clouding, faded colors, glare, halos, poor night sight, or prescription changes may signal cataracts ². Talk with your eye doctor because these symptoms can also signal other eye problems ⁶.

Make an appointment for an eye exam if you notice any changes in your vision ⁷. If you develop sudden vision changes, see a member of your healthcare team right away ⁷.

A comprehensive eye exam is the best way to check for cataracts and assess overall eye health ². Dilated exams use special drops to widen pupils and check tissues at the back ². Doctors review symptoms and health history, then test sight and check other causes ¹. Your eye doctor reviews your health history and gives your eyes a full exam ¹⁰.

A visual acuity test uses an eye chart to measure how well you can read letters ¹⁰. For a sight test, the doctor covers one eye and tests the other alone ¹⁰. A slit lamp uses bright light and a microscope to show precise details inside your eye ¹⁰. The slit-lamp examination can reveal a cataract in the lens and check other eye structures ¹⁰.

An eye-pressure test uses a device to measure pressure inside your eye ¹⁰. Dilating drops widen pupils, allowing more light to enter so providers can see tissues at the back ². New glasses and brighter lighting may improve vision for people with cataracts ². Surgery is the only way to remove a cataract ².

Surgery may be an option when cataracts interfere with everyday activities ². During surgery, the doctor replaces the cloudy natural lens with an artificial lens ². Talk with your eye doctor about whether surgery is right for you ¹⁰. Surgery is the only way to remove a cataract from an affected person's eye ².

During cataract surgery, the doctor removes the cloudy natural lens from the affected eye ⁶. In the same surgery, the doctor may replace the removed cloudy lens with an artificial lens ⁶. When used, the artificial lens, called an intraocular lens or IOL, stays in the treated eye ^6,9. When used, the artificial lens takes the natural lens's place and remains permanently in the treated eye ¹⁰.

Cataract surgery can fix vision problems from cataracts and help people see clearly ⁶. After cataract surgery, 9 out of 10 people see better ⁶. Cataract surgery improves vision for most, but not all, people who receive it ⁸. Your cataracts start getting in the way of everyday activities—doctors might suggest surgery ⁶.

New glasses or brighter lighting may improve vision, but those measures do not remove the cataract ². At first, new glasses and brighter lighting may improve your vision and help you see more clearly ². Anti-glare sunglasses and magnifying lenses may help manage cataracts during reading and other tasks ⁶. New glasses and brighter lighting may improve vision, but only surgery removes a cataract ².

Only surgery removes a cataract; practical changes can only improve vision ². Your doctor might suggest surgery if your cataracts start getting in the way of reading or driving ⁶. During surgery, the doctor replaces the clouded natural lens with an artificial lens ⁹. The artificial lens in your eye is called an intraocular lens, or IOL ⁶.

After cataract surgery, 9 out of 10 people can see better than they did before ⁶. Cataract surgery is generally safe but risks infection, bleeding, and a detached retina ¹⁰. Retinal detachment means the retina is pulled out of place, and surgery increases this risk ¹⁰. Swelling called cystoid macular edema and posterior capsule opacification are common cataract surgery problems ⁵.

Posterior capsule opacification clouds tissue behind the artificial lens; laser surgery can fix it ⁸. Cataract surgery can improve sight and daily life for many people with cataracts ⁵.