On this page

Basics

• Summary
• Start Here
• Diagnosis and Tests
• Treatments and Therapies

Learn More

• Related Issues
• Specifics
• Genetics

See, Play and Learn

• Images
• Videos and Tutorials

Research

• Statistics and Research
• Clinical Trials
• Journal Articles

Resources

• Reference Desk
• Find an Expert

For You

• Children
• Older Adults
• Patient Handouts

Summary

A cataract is a clouding of the lens in your eye. It affects your vision. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.

A cataract can occur in either or both eyes. It cannot spread from one eye to the other. Common symptoms are:

• Blurry vision
• Colors that seem faded
• Glare - headlights, lamps or sunlight may seem too bright. You may also see a halo around lights.
• Not being able to see well at night
• Double vision
• Frequent prescription changes in your eye wear

Cataracts usually develop slowly. New glasses, brighter lighting, anti-glare sunglasses or magnifying lenses can help at first. Surgery is also an option. It involves removing the cloudy lens and replacing it with an artificial lens. Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay cataracts.

NIH: National Eye Institute

Start Here

• Facts about Cataract (National Eye Institute) Also in Spanish
• What Are Cataracts? (American Academy of Ophthalmology) Also in Spanish

Diagnosis and Tests

• Dilating Eye Drops (American Association for Pediatric Ophthalmology and Strabismus)
• Eye Exam and Vision Testing Basics (American Academy of Ophthalmology) Also in Spanish
• Preoperative Testing (American Academy of Ophthalmology)

Treatments and Therapies

• Cataract Surgery (American Academy of Ophthalmology) Also in Spanish
• Cataract surgery - series -- Normal anatomy (Medical Encyclopedia) Also in Spanish
• IOL Implants: Lens Replacement after Cataracts (Intraocular Lenses) (American Academy of Ophthalmology) Also in Spanish

Related Issues

• Facts and Myths about Cataracts (Prevent Blindness America) - PDF
• Intraocular Lens Dislocation (American Society of Retina Specialists)
• Retained Lens Fragments (American Society of Retina Specialists)

Specifics

• Cloudy Vision? It Could be Cataracts (National Institutes of Health)
• What Do Cataracts Look Like? (American Academy of Ophthalmology) Also in Spanish

Genetics

• Autosomal dominant optic atrophy and cataract: MedlinePlus Genetics (National Library of Medicine)
• Hyperferritinemia-cataract syndrome: MedlinePlus Genetics (National Library of Medicine)

Images

• Cataracts (VisualDX)

Videos and Tutorials

• Cataract (Medical Encyclopedia) Also in Spanish

Statistics and Research

• Eye Health Data and Statistics (National Eye Institute) Also in Spanish

Clinical Trials

• ClinicalTrials.gov: Cataract (National Institutes of Health)
• ClinicalTrials.gov: Lenses, Intraocular (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Light-adapted electroretinograms of eyes with cataract recorded using the HE-2000 system...
• Article: Impact of morphological variations on preoperative and postoperative central corneal thickness...
• Article: G91-deletion in βA3/A1-crystallin induces cellular and molecular changes in mouse lenses...
• Cataract -- see more articles

Reference Desk

• How the Eyes Work (National Eye Institute) Also in Spanish
• NEI for Kids: Glossary (National Eye Institute)

Find an Expert

• American Foundation for the Blind
• Find an Ophthalmologist (American Academy of Ophthalmology) Also in Spanish
• Finding an Eye Doctor (National Eye Institute)
• National Eye Institute

Children

• Cataract (American Association for Pediatric Ophthalmology and Strabismus)
• Intraocular Lens Implant (IOL) (American Association for Pediatric Ophthalmology and Strabismus)

Older Adults

• Aging and Health: Cataracts (AGS Health in Aging Foundation)

Patient Handouts

• Cataract - adult (Medical Encyclopedia) Also in Spanish
• Cataract removal (Medical Encyclopedia) Also in Spanish
• Slit-lamp exam (Medical Encyclopedia) Also in Spanish
• Standard eye exam (Medical Encyclopedia) Also in Spanish