Cataracts is one of the most common causes of vision problems, particularly as people get older. A cataract develops when the normally clear lens inside the eye becomes cloudy, making it harder for light to pass through and form a sharp image on the retina.

Cataracts usually develop gradually. At first, a person may not notice any significant change in vision. As the clouding becomes more pronounced, however, everyday activities such as reading, driving, recognizing faces, or seeing clearly in low light may become more difficult.

Although aging is the most common reason cataracts develop, they can also occur because of eye injuries, certain medical conditions, some medications, previous eye surgery, radiation exposure, genetics, and other factors.

The good news is that cataracts are treatable. When a cataract begins to interfere significantly with everyday activities, cataract surgery can remove the cloudy natural lens and replace it with an artificial lens.

This guide explains what cataracts are, how they develop, their symptoms and causes, different types, prevention, and more.

What Are Cataracts?

A cataract is a cloudy area that develops in the natural lens of the eye.

The lens is a transparent structure located behind the iris, the colored part of the eye. Its job is to focus incoming light onto the retina at the back of the eye. When the lens becomes cloudy, light cannot pass through it as clearly. This can gradually make vision:

• Blurry
• Hazy
• Dim
• Less sharp
• Less colorful

A cataract may affect one eye or both eyes. It does not spread from one eye to the other, although cataracts can develop independently in both eyes.

Facts About Cataracts

Fact	Information
What is a cataract?	Clouding of the natural lens inside the eye
Most common cause	Age-related changes in the lens
Common symptoms	Blurry vision, glare, faded colors, poor night vision, and halos around lights
Can cataracts affect both eyes?	Yes, although one eye may be affected more than the other
Can children develop cataracts?	Yes, although childhood cataracts are less common
Can glasses cure cataracts?	No. Glasses may improve vision temporarily when cataracts are mild, but they do not remove the cataract
Main treatment	Cataract surgery when vision becomes significantly affected
Can cataracts be prevented completely?	Not always, but some measures may reduce risk
Can cataracts cause vision loss?	Yes, untreated cataracts can eventually cause significant vision impairment

How Do Cataracts Develop?

The lens contains proteins and other structures that normally remain organized and transparent. As the eye ages, changes occur within the lens. Proteins can become damaged or clump together, causing areas of cloudiness.

At first, the cloudy area may be small and have little effect on vision. Over time, however, the clouding can become more extensive. As more light is scattered or blocked, vision becomes increasingly blurred or hazy.

The exact process can vary depending on the type of cataract.

Symptoms of Cataracts

Cataracts usually develop slowly, so symptoms may not be obvious in the beginning. As the cataract progresses, you may notice:

Blurry or Cloudy Vision

Objects may no longer appear as sharp as they once did. You may feel as though you are looking through:

• Fog
• A dirty window
• A thin veil
• Hazy glass

The amount of blurriness can gradually increase.

Difficulty Seeing at Night

Cataracts can make low-light vision more difficult. You may notice problems when:

• Walking outside at night
• Reading in dim lighting
• Driving at night
• Seeing objects in poorly lit rooms

Night-time vision can become particularly challenging when headlights or streetlights create excessive glare.

Sensitivity to Bright Light

Bright sunlight, lamps, headlights, or other strong light sources may become uncomfortable. Some people experience increased glare that makes it harder to see clearly.

Halos Around Lights

You may notice circles or glowing rings around:

• Streetlights
• Car headlights
• Lamps
• Other bright light sources

This can be particularly noticeable in dark environments.

Faded or Yellowish Colors

Cataracts can change the way colors appear. Colors may gradually seem:

• Less vivid
• Faded
• Duller
• More yellow or brown

This change can happen slowly enough that a person may not recognize it at first.

Frequent Changes in Glasses Prescription

Some people notice that their glasses or contact lens prescription seems to change more frequently than usual.

A new prescription may temporarily improve vision, but it cannot remove the cataract itself.

Double Vision in One Eye

Cataracts can sometimes cause double vision in one eye. However, double vision has many possible causes, so new or sudden double vision should be assessed by an eye-care professional.

Difficulty Reading

As vision becomes cloudier, reading may become harder. You may need:

• Brighter lighting
• Larger print
• Magnification
• More frequent changes in glasses

Types of Cataracts

Cataracts can be classified according to where they develop within the lens or how they develop.

1. Age-Related Cataracts

These are the most common type. They develop as natural changes occur within the lens over time.

2. Nuclear Cataracts

A nuclear cataract develops in the central part of the lens. It can gradually affect distance vision and may cause the lens to become increasingly yellow or brown.

3. Cortical Cataracts

Cortical cataracts develop in the outer portion of the lens. They may produce glare and problems with light scattering.

4. Posterior Subcapsular Cataracts

These develop toward the back of the lens. They can interfere with both near and distance vision and may cause significant sensitivity to bright light. Some posterior subcapsular cataracts can progress more quickly than other types.

5. Traumatic Cataracts

An injury to the eye can damage the lens and cause a cataract. A traumatic cataract may appear relatively soon after an injury or develop years later.

6. Congenital or Childhood Cataracts

Cataracts can occasionally be present at birth or develop during childhood. They may be associated with:

• Genetic conditions
• Certain infections
• Eye injuries
• Other childhood health conditions
• Problems affecting the eye

Cataracts that significantly interfere with a child’s developing vision require prompt evaluation.

7. Secondary Cataracts

A cloudy area can sometimes develop in the membrane behind an artificial lens after cataract surgery. This is commonly called a secondary cataract, although the medical term is posterior capsule opacification.

It is not the original cataract growing back. A laser procedure can usually treat this type of clouding.

What Causes Cataracts?

Aging is the most common cause of cataracts, but several other factors can contribute.

Aging

As people get older, natural changes occur within the proteins and fibers of the lens. These changes can gradually reduce lens transparency.

Diabetes

Diabetes is associated with an increased risk of developing cataracts.

Long-term problems with blood glucose can affect different tissues throughout the body, including the eyes. Good management of diabetes is therefore important for overall eye health.

Eye Injuries

An injury to the eye can damage the lens and cause clouding. Protective eyewear can help reduce the risk of eye injuries during activities where objects or particles could enter the eye.

Previous Eye Surgery

Some types of eye surgery may increase the likelihood of developing a cataract later.

Long-Term Steroid Use

Long-term use of corticosteroid medications can increase the risk of certain cataracts. If you take prescribed steroids, do not stop them on your own. Discuss possible side effects with your healthcare professional.

Radiation Exposure

Certain types of radiation can increase cataract risk. This may include radiation used during some medical treatments.

Smoking

Smoking is associated with an increased risk of cataracts. Quitting smoking can benefit overall health as well as eye health.

Risk Factors for Cataracts

Factors associated with increased cataract risk include:

• Increasing age
• Diabetes
• Family history
• Smoking
• Excessive alcohol consumption
• Long-term corticosteroid use
• Previous eye injury
• Previous eye surgery
• Certain eye diseases
• Significant exposure to ultraviolet radiation
• Certain radiation treatments

Having one or more risk factors does not mean that you will definitely develop cataracts.

How Are Cataracts Diagnosed?

An eye doctor can usually identify cataracts during a comprehensive eye examination. The examination may include:

Visual Acuity Test

This checks how clearly you can see at different distances.

Dilated Eye Examination

Eye drops are used to enlarge the pupil, allowing the eye doctor to examine the lens, retina, optic nerve, and other structures more closely.

Slit-Lamp Examination

A specialized microscope allows the eye doctor to examine the structures at the front of the eye in detail.

Eye Pressure Measurement

Eye pressure may also be checked as part of a comprehensive eye examination. The examination can help determine whether cataracts are present and whether another eye condition could be contributing to the vision changes.

How Are Cataracts Treated?

Treatment depends on how much the cataract affects your vision and daily activities.

Stronger Lighting

When cataracts are mild, brighter lighting may make reading and other close-up activities easier.

Updated Glasses

A new glasses prescription can sometimes improve vision during the earlier stages of cataract development. However, glasses do not remove the cataract.

Anti-Glare Measures

Reducing glare and using appropriate lighting may make certain activities more comfortable.

Cataract Surgery

When cataracts significantly interfere with daily life, cataract surgery is the definitive treatment. During the procedure, the cloudy natural lens is removed and replaced with an artificial lens called an intraocular lens (IOL).

Cataract surgery is generally performed as an outpatient procedure. The eye is numbed, the cloudy lens is removed, and the artificial lens is positioned inside the eye. Most people do not need to stay overnight in a hospital.

The timing of surgery depends on how much the cataract is affecting your vision and daily activities.

When Should You Consider Cataract Surgery?

There is no universal point at which everyone with a cataract must have surgery. Your eye doctor may discuss surgery when cataracts begin interfering with activities such as:

• Reading
• Driving
• Working
• Watching television
• Recognizing faces
• Moving around safely
• Performing everyday tasks

The decision should be made with an eye-care professional after considering your vision, lifestyle, overall eye health, and the potential benefits and risks of surgery.

Tips to Prevent Cataracts

There is no guaranteed way to prevent every cataract because aging is an important contributor. However, several habits may help protect eye health and potentially reduce risk.

Protect Your Eyes From UV Radiation

When spending time outdoors, sunglasses that provide appropriate ultraviolet protection can help protect the eyes from excessive UV exposure.

A wide-brimmed hat can provide additional protection.

Don’t Smoke

Smoking is associated with cataract development. Avoiding tobacco is beneficial for both eye health and overall health.

Manage Diabetes

If you have diabetes, following your treatment plan and maintaining appropriate blood glucose control can help reduce the risk of diabetes-related eye complications.

Protect Your Eyes From Injury

Wear appropriate protective eyewear during activities where your eyes could be injured. This is particularly important when working with tools, chemicals, or materials that could strike the eye.

Eat a Balanced Diet

A varied diet containing fruits, vegetables, leafy greens, whole grains, nuts, and other nutrient-rich foods supports overall health and provides nutrients important for eye function.

Limit Excessive Alcohol

Heavy alcohol consumption is associated with several health problems and may increase cataract risk.

Note:

A cataract is a structural change in the lens and does not disappear on its own. Lifestyle measures can support eye health, and glasses may improve vision temporarily when cataracts are mild, but they do not remove the cloudy lens. When a cataract significantly affects vision, surgery is the treatment that removes it.

Untreated cataracts can eventually cause severe vision impairment. However, cataract-related vision loss is generally treatable with surgery. The outcome depends on factors such as the health of the rest of the eye and whether other eye diseases are present.

When Should You See an Eye Doctor?

Make an appointment for an eye examination if you notice:

• Gradually worsening blurry vision
• Difficulty seeing at night
• Increasing glare
• Halos around lights
• Faded colors
• Frequent changes in your glasses prescription
• Difficulty reading
• Vision changes that interfere with everyday activities

Not every vision change is caused by cataracts. Conditions such as glaucoma, retinal disease, refractive errors, and other eye disorders can produce similar symptoms.

When Is a Vision Change an Emergency?

Cataracts usually develop gradually and are not an emergency.

However, sudden changes in vision should not be assumed to be cataracts. Seek urgent medical attention if you experience:

• Sudden loss of vision
• Sudden severe eye pain
• Sudden flashes of light
• A sudden increase in floaters
• A curtain-like shadow over your vision
• Sudden double vision
• Severe headache accompanied by vision changes

These symptoms can have causes other than cataracts and may require urgent assessment.

Myth vs. Fact

Myth	Fact
Cataracts only happen to very old people.	Cataracts are more common with aging, but they can occur in younger adults and children.
Cataracts are caused by reading too much.	Reading does not cause cataracts.
Cataracts spread from one eye to the other.	Cataracts can develop in both eyes, but one cataract does not spread to the other eye.
Stronger glasses cure cataracts.	Glasses may temporarily improve vision, but they do not remove the cataract.
Cataracts always need immediate surgery.	Surgery is generally considered when the cataract significantly affects vision and daily activities.
Cataract surgery replaces the entire eye.	Surgery removes the cloudy natural lens and replaces it with an artificial intraocular lens.
Cataracts cannot be treated.	Cataracts can be treated effectively with surgery when they significantly affect vision.
Cataracts always cause painful eyes.	Cataracts typically cause gradual vision changes rather than eye pain.

Frequently Asked Questions

What are the first symptoms of cataracts?

Early cataracts may cause no noticeable symptoms. As they progress, common symptoms include blurry or cloudy vision, glare, difficulty seeing at night, faded colors, halos around lights, and frequent changes in glasses prescriptions.

At what age do cataracts usually start?

Cataracts become increasingly common with age, but there is no single age at which they begin. Some people develop them earlier because of genetics, medical conditions, medications, injuries, or other factors.

Can cataracts affect only one eye?

Yes. Cataracts can occur in one eye or both eyes. When both eyes are affected, one may be more advanced than the other.

Can cataracts be removed without surgery?

No. There is currently no medication, eye drop, or supplement that removes an established cataract. Surgery is the definitive treatment when a cataract significantly affects vision.

Can cataracts come back after surgery?

The original cataract does not grow back because the cloudy natural lens has been removed. However, clouding can sometimes develop in the membrane behind the artificial lens. This is called posterior capsule opacification and can usually be treated with a laser procedure.

Conclusion

Cataracts develop when the normally clear lens inside the eye becomes cloudy. They are particularly common as people age, but they can also occur because of diabetes, eye injuries, certain medications, previous eye surgery, radiation exposure, genetics, and other factors.

The condition usually progresses gradually. Early symptoms may be subtle, but blurry vision, increased glare, difficulty seeing at night, faded colors, halos around lights, and frequent changes in glasses prescriptions can become more noticeable as a cataract develops.

Regular eye examinations are important because vision changes are not always caused by cataracts. Other eye conditions can produce similar symptoms and may require different treatments.

When a cataract begins interfering with reading, driving, work, or other everyday activities, an eye doctor can discuss treatment options. Cataract surgery can remove the cloudy natural lens and replace it with an artificial lens, restoring clearer vision for many people.

Protecting your eyes from excessive UV exposure, avoiding smoking, managing conditions such as diabetes, protecting your eyes from injury, and maintaining a healthy lifestyle can all contribute to better long-term eye health.

Recommended External References

Readers seeking additional information can consult:

• National Eye Institute (NEI)
• NHS – Cataracts in Adults
• Mayo Clinic – Cataracts

Disclaimer

This article is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment. Vision changes can have many different causes and should not automatically be assumed to be cataracts. If you experience persistent changes in vision, consult a qualified eye-care professional for appropriate examination and diagnosis. Sudden vision loss, sudden severe eye pain, flashes of light, or other sudden visual changes require urgent medical evaluation.

Reviewed and Written by the HealthVineHub Medical Editorial Team

This article was prepared by an experienced medical content writer and reviewed using current medical and scientific information from reputable eye-health organizations and clinical resources. Our editorial team is committed to producing accurate, evidence-based, reader-friendly health information that supports informed healthcare decisions.