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Eye Problems and Diseases


Have questions about an eye condition or vision problem? Browse our extensive list of doctor-written and doctor-reviewed articles for reliable, easy-to-understand information.

Please keep in mind that these articles are for general education purposes only. If you suspect you have an eye condition or vision problem or you have injured your eye, see an eye doctor immediately.

Acanthamoeba Keratitis

A rare but serious eye infection associated with poor contact lens hygiene and other factors.

Amblyopia (Lazy Eye)

Amblyopia is a vision development problem in infants and young children that can lead to permanent vision loss. Learn the symptoms, causes and treatments.

Anisocoria - New!

Is one pupil bigger than the other? Learn about anisocoria (unequal pupils).


Usually caused by an irregular cornea, astigmatism causes blur at all distances. Also see the Eye Doctor Q&A on astigmatism.

Bell's Palsy

This condition causes sudden paralysis of one side of the face. Because it affects blinking, it can cause severe dry eye.

Bionic Eye Implants

Learn about retinal implants that are restoring functional vision to people with retinitis pigmentosa and other blinding conditions.

Black Eye

How serious is a black eye? How to treat black eyes.


Inflammation of the eyelids associated with chronic eye irritation, watery eyes, foreign body sensation, sensitivity to light and crusty debris at the base of the eyelashes.

Blurry Vision

Blurry vision has many causes, from fatigue and eyestrain to serious eye diseases such as glaucoma. A video helps explain blurry vision causes and treatments.

Burning Eyes

How to get relief from burning, stinging eyes.


The risk of cataracts increases with age. Learn what causes them and how to protect your eyes.
See also: Cataract FAQ | Eye Doctor Q&A | Congenital Cataracts

Cataract Surgery

It's the most common non-elective surgery in the United States. Recent innovations include laser-assisted cataract surgery.
See also: Cataract Surgery Cost | Cataract Surgery Recovery | Choosing a Cataract Surgeon | Cataract Surgery Complications | Intraocular Lenses (IOLs) | Crystalens & Accommodating IOLs | Multifocal IOLs | Mixing Multifocal Lenses | IOLs for Presbyopia FAQ | Toric IOLs for Astigmatism | A Cataract Surgeon Undergoes Cataract Surgery


A swollen bump in the eyelid. Learn about causes and treatments.

Clinical Trials Related to Eye Diseases

Find out the status of clinical trials for treatment of glaucoma, macular degeneration, blepharitis and other eye problems and diseases.

CMV Retinitis

About 80 percent of adults have been exposed to the cytomegalovirus (CMV), but it mostly affects people with poor immune systems, such as AIDS patients.

Color Blindness

Learn the varieties of color vision deficiency and how to cope with color blindness.
See also: Color Blind Glasses

Common Eye Disorders

How to identify and manage everyday eye problems.

Concussion, TBI and Vision - New!

Up to 90 percent of people who suffer from concussion or other traumatic brain injury experience vision problems such as blurry vision, sensitivity to light and difficulties with eye movements. Learn what can be done.

Conjunctivitis (Pink Eye)

What you can do about redness, swelling, itching and tearing of pink eye. (Also available: conjuntivitis en español.) Learn about pink eye treatment and the various conjunctivitis types. Find out answers to common questions such as how long pink eye lasts, how to get rid of pink eye and how long pink eye is contagious.

Cornea Transplant

Eye injuries and diseases like keratoconus may require a cornea transplant, using healthy tissue from an eye donor.

Corneal Abrasion (Scratched Eye)

A scratched cornea is usually very painful. What to do if it happens to you.

Corneal Cross-Linking

Corneal cross-linking (CXL) is a minimally invasive outpatient procedure for the treatment of progressive keratoconus. CXL creates new links connecting collagen fibers in the cornea to strengthen and stabilize the clear front surface of the eye.

Corneal Ulcer

Treatment may help prevent scarring on your eye.

Detached Retina

Flashes of light and floating spots are classic warning signs of a detached retina — get them checked out ASAP. Also read our Eye Doctor Q&A on retinal problems.

Diabetic Retinopathy

Damage to the eye's retina due to diabetes. Also read about treatment for diabetic retinopathy and macular edema. More details are found in our Eye Doctor Q&A on how diabetes affects your eyes and our diabetic retinopathy FAQ.

Different Colored Eyes (Heterochromia)

Many people (and animals) have two different colored eyes. What causes it? Is it a problem that requires an eye exam?

Dilated Pupils - New!

What causes larger-than-normal pupils and what to do about it.

Double Vision (Diplopia)

Many conditions cause double vision, including stroke and cataracts. What to do.

Dry Eye Infographic - Sponsored

Learn eight symptoms, causes and steps to managing dry eye.

Dry Eye Syndrome

Why eyes get dry. Also read about dry eye treatments and relief, such as eye drops, tear duct (punctal) plugs and nutritional supplements for more eye moisture. Also, see the dry eye doctor's answers to reader questions. To learn more, view details about how punctal plugs work and our FAQ on dry eyes and the best contact lenses for them.

Eye Allergies

Itchy, red, swollen, tearing eyes may mean eye allergies. Get tips for relief, and read our Eye Doctor Q&A about common eye allergy symptoms.

Eye and Vision News

Breaking news about eye care and vision problems.

Eye and Vision Product News

New eyewear and vision care products designed to improve your life.

Eye Herpes

Ocular herpes is a recurrent viral infection that may lead to serious vision loss. Read how herpes of the eye is transmitted and treated.

Eye Infections

Learn about bacterial, viral and fungal eye infections, including symptoms.

Eye Injury: A Guide to Treatment

Accidents cause many kinds of eye injuries, from corneal scratches to penetrating wounds. What to do for an eye emergency.

Eye Occlusions (Eye Strokes)

Sudden vision loss can occur when a clot or blockage interrupts blood flow to vital eye structures.

Eye Pain

How to know if a painful eye is an emergency.

Eye Symptoms A to Z

A list of nearly 100 eye symptoms and the problems and diseases associated with them.

Eye Twitching

Eyelid twitches, tics and spasms are maddening. Here are eight remedies you can try.

Floaters, Flashes and Spots

Eye floaters and flashes may be harmless, or they may signal a serious problem, like a detached retina.

Fuchs' Corneal Dystrophy

Causes loss of vision and clouding of the cornea due to degeneration of the corneal endothelium and corneal edema.


Glaucoma damages the optic nerve and diminishes the field of vision. Learn about glaucoma causes, eye drops for glaucoma, narrow-angle glaucoma, primary open-angle glaucoma and glaucoma surgery.
See also: Eye Doctor Q&A | Glaucoma News & Research | Glaucoma FAQ

Glaucoma Surgery

New options for controlling glaucoma with surgery.

Higher-Order Aberrations

Higher-order aberrations (HOAs) are vision errors causing poor night vision or double images.

Hyperopia (Farsightedness)

Farsighted people can have poor near vision or blurred vision at all distances.

Hyphema - New!

A hyphema is a broken blood vessel in the eye that causes blood to collect in the space between the cornea and iris. It's usually painful and can cause glaucoma.

Intacs for Keratoconus

These tiny corneal inserts can help flatten a bulging eye.

Itchy Eyes

What causes itchy eyes and eyelids — and how to get relief.


Special contact lenses can help this condition that changes the shape of your eye. You can read answers to reader questions on our Ask the Eye Doctor About Keratoconus page. Also read more about keratoconus on our Keratoconus FAQ and Intacs for Keratoconus pages.

Losing an Eye: Enucleation and Prosthetic Eye FAQ

FAQ about eye removal surgery (enucleation) and glass eyes.

Macular Degeneration (AMD)

Our 10-page section covers this sight-threatening disease, plus FDA-approved macular degeneration treatments, investigational treatments, macular degeneration prevention, how to use an Amsler Grid and the Lucentis vs. Avastin treatment debate. Stargardt's disease is a form of macular degeneration that can affect children.
See also: AMD News | Eye Doctor Q&A | FAQ

Macular Dystrophy

Central vision loss can be associated with this inherited eye disease.

Macular Hole

Suddenly blurry or distorted vision, especially in seniors and diabetics, may mean a macular hole.

Meibomian Gland Dysfunction

MGD is the culprit behind most cases of dry eye syndrome. Find out how to spot it and what you can do to get relief.

Milia (Eyelid Cysts) - New!

What causes those tiny eyelid cysts in babies and adults, and how they are treated.

Myopia (Nearsightedness)

Nearsighted people can see fine up close, but distant objects are a blur.


Uncontrollable eye movements from nystagmus often have neurological causes.

Ocular Hypertension

High eye pressure has no symptoms, but can be easily detected in an eye exam. Learn what can be done to prevent glaucoma and possible eye damage.

Ocular Migraine

Ocular migraine causes a sensation of looking through shattered glass. What's happening? Also, read our Eye Doctor Q&A about ocular migraines.

Ocular Rosacea

How to solve eye and eyelid irritation.

Optic Neuritis and Optic Neuropathy

An inflamed optic nerve can cause blurry vision and blind spots.

Peripheral Vision Loss

"Tunnel vision" can have various causes, including glaucoma.

Photophobia (Light Sensitivity)

Sensitive to light? Many eye conditions can cause this problem.


Pingueculae are growths on the eye. Are they serious?


All about this normal age-related loss of focusing ability that becomes noticeable after age 40. Also, read answers to frequently asked questions for a quick overview.


Pterygia, also called "surfer's eye," are growths on the eyeball that can interfere with vision.

Ptosis (Drooping Eyelid)

Drooping eyelids can be corrected with ptosis repair surgery, which tightens the muscle that supports the upper eyelid.

Red Eyes

Red eyes can be caused by allergies, eye infections and eye injuries. Learn more causes of red eye and how to treat bloodshot eyes.

Eye News

Visual Test with Flickering Lights May Be Easier Than an MRI to Check Cognitive Function

Drawing of a brain with lights inside.

Until recently, detecting dementia and other cognitive issues required lengthy tests, such as an MRI.

But researchers at the University of Georgia have discovered that a simple technique that measures visual processing speed can more easily provide information about executive cognitive abilities.

Executive cognitive abilities include shifting attention between different tasks, planning, organizing and problem solving.

Performing the test is quick and easy. You simply look into a device inside of which two wavelengths of light flash at increasingly fast speeds. Eventually, you stop recognizing the flash and start to see a circle instead. This is the point at which "critical flicker fusion" (CFF) occurs.

Retinitis Pigmentosa

Poor night vision and a narrowing field of vision beginning in childhood herald this rare disorder. Can vitamin A and beta-carotene help? Also read our Eye Doctor Q&A on retinal problems.

Sjogren's Syndrome

Dry eye is a common symptom of this autoimmune disorder.

Sleep in Your Eyes

Do you often wake up with sticky, slimy, crusty "eye gunk"? This article explains where eye discharge comes from and when it's cause for alarm.

Snow Blindness

How to prevent a painful sunburned eye and temporary vision loss from UV exposure.

Stargardt's Disease (STGD)

A form of macular degeneration that affects children and young people.


Key facts about strabismus and crossed eyes, including causes and treatments (strabismus surgery, vision therapy and orthoptics).

Strabismus Surgery

These procedures adjust eye muscles to straighten misaligned eyes. Also, read an Eye Doctor Q&A about what to expect from strabismus surgery.


What causes styes in your eyelid — and how to prevent them.

Stye Treatment - New!

How to get rid of a stye and keep them from coming back.

Subconjunctival Hemorrhage

Sudden redness in the white of your eye may be a subconjunctival hemorrhage.

Swollen Eyelids

Swollen eyes have many causes. Here are tips for prevention and treatment.


Painful inflammation of the uvea causes light sensitivity, floaters and blurred vision.

Vitrectomy & Vitreoretinal Procedures

These delicate surgical procedures for macular holes, retinal detachments and other conditions are performed in the eye's deep interior.

Page updated December 14, 2018