Some Causes and Features of Eye Redness
Some Causes and Features of Eye Redness
| Cause | Common Features* | Diagnostic Approach† |
| Conjunctival disorders and episcleritis‡ | ||
| Allergic or seasonal conjunctivitis Allergic Conjunctivitis Allergic conjunctivitis is inflammation of the conjunctiva caused by an allergic reaction. Allergic reactions caused by, for example, airborne allergens, may inflame the conjunctiva. Redness... read more | Affecting both eyes An itching or scratching sensation and tearing In people with known allergies or other features of allergies (such as a runny nose that recurs during certain seasons) Sometimes in people who use eye drops (particularly neomycin) | A doctor's examination alone |
| Chemical (irritant) conjunctivitis | An itching or scratching sensation and tearing Exposure to potential irritants (such as dust, smoke, ammonia, or chlorine) | A doctor's examination alone |
| Episcleritis Episcleritis Episcleritis is inflammation of the tissue lying between the sclera (the tough, white, fiber layer covering the eye) and the conjunctiva (the membrane that lines the eyelid and covers the white... read more | Affecting only one eye A spot of redness on the white of the eye Mild irritation of the eye | A doctor's examination alone |
| An itching or scratching sensation, tearing, and sensitivity to light Sometimes a discharge from the eye and eyelid swelling Sometimes swollen lymph nodes in front of the ears | A doctor's examination alone | |
| Affecting only one eye A red patch or large area of redness (that looks like blood or ketchup) No tearing, irritation, itching, change in vision, pain, or discharge from the eye Sometimes in people who have had an eye injury, sneezed violently, or tried to exhale without letting air escape, as may occur during a bowel movement or while lifting a heavy weight (called the Valsalva maneuver) Often in people known to use drugs that help prevent blood from clotting (such as aspirin or warfarin) | A doctor's examination alone | |
| Corneal disorders§ | ||
| Contact lens keratitis Amebic Keratitis (Eye Infection) Amebic keratitis is a rare infection of the cornea (the clear layer in front of the iris and pupil of the eye) caused by Acanthamoeba species, free-living amebas. It usually occurs in people... read more (inflammation of the cornea—the clear layer in front of the iris and pupil) | Eye ache, redness, tearing, and sensitivity to light In people who have worn their contact lenses for too long | A doctor's examination alone |
| Corneal scratch Corneal Abrasions and Corneal Foreign Bodies Foreign bodies in the cornea cause abrasions, resulting in pain and redness, and lead to infections, even after they are removed. Most of these injuries are minor. (See also Overview of Eye... read more (abrasion) or foreign object Corneal Abrasions and Corneal Foreign Bodies Foreign bodies in the cornea cause abrasions, resulting in pain and redness, and lead to infections, even after they are removed. Most of these injuries are minor. (See also Overview of Eye... read more (body) | Symptoms that begin after an eye injury (which may not have been noticed in infants and young children) Pain when blinking and a foreign body sensation | A doctor's examination alone |
| Sometimes a grayish patch on the cornea that later becomes an open, painful sore Sometimes in people who have had an eye injury or who slept with their contact lenses in | A doctor's examination Culture of a sample taken from the ulcer (done by an ophthalmologist) | |
| Epidemic keratoconjunctivitis Infectious Conjunctivitis Infectious conjunctivitis is inflammation of the conjunctiva usually caused by viruses or bacteria. Bacteria and viruses can infect the conjunctiva. Redness and tearing or discharge are common... read more | Watery discharge Eyelid swelling, enlarged lymph nodes and bulging of conjunctiva Sometimes temporary loss of vision | A doctor's examination alone |
| Herpes simplex keratitis Herpes Simplex Keratitis Herpes simplex keratitis is an eye infection that involves the cornea (the clear layer in front of the iris and pupil) and is caused by herpes simplex virus. Eye pain, tearing, redness, a feeling... read more | Affecting only one eye Early: Blisters on the eyelid and/or crusting Late or recurring: Eye redness and tearing, eye pain, impaired vision, and sensitivity to light | A doctor's examination Sometimes, testing for the virus in scrapings obtained from the surface of the cornea or from blisters around the eye |
| Herpes zoster ophthalmicus Herpes Zoster Ophthalmicus Herpes zoster ophthalmicus is infection of the eye caused by the varicella-zoster virus, the virus that causes chickenpox and shingles. Symptoms include tingling of the forehead, blisters on... read more | Affecting only one eye Early: A rash with fluid-filled blisters and/or crusting on one side of the face, around the eye, on the forehead, and/or on the tip of the nose, and sometimes pain Eye redness, tearing, and eyelid swelling Late: Eye redness, usually sensitivity to light, and usually severe pain | A doctor's examination Sometimes, testing for the virus in scrapings obtained from blisters around the eye |
| Other disorders | ||
| Severe eye ache and redness Headache, nausea, vomiting, and pain with exposure to light Disturbances in vision such as seeing halos around lights and/or decreased vision | Measurement of pressure inside the eye (tonometry) and examination of the eye's drainage channels with a special lens (gonioscopy), done by an ophthalmologist | |
| Anterior uveitis Uveitis Uveitis is inflammation anywhere in the pigmented inside lining of the eye, known as the uvea or uveal tract. The uveal tract may become inflamed because of infection, injury, a bodywide autoimmune... read more (inflammation of the anterior chamber—the fluid-filled space between the iris and cornea) | Eye ache and sensitivity to light Eye redness (particularly around the cornea) Blurring or loss of vision Often in people who have an autoimmune disorder or who recently had an eye injury | A doctor's examination alone |
| Scleritis Scleritis Scleritis is severe, destructive inflammation of the sclera (the tough, white, fiber layer covering the eye) that may threaten vision. Scleritis sometimes occurs in people who have a bodywide... read more (inflammation of the white of the eye, called the sclera) | Pain, often described as boring, and severe enough to wake someone from a sound sleep Sensitivity to light Tearing Red or violet patches on the white of the eye Often in people who have an autoimmune disorder | A doctor's examination Sometimes, ultrasound, or CT of the orbits Rarely, biopsy |
| * Features include symptoms and the results of the doctor's examination. Features mentioned are typical but not always present. † Although a doctor's examination is always done, it is mentioned in this column only if the diagnosis can sometimes be made only by the doctor's examination alone, without any testing. If an ophthalmologist's examination is specifically required, that is mentioned separately. ‡ Conjunctival disorders usually cause itching or a scratchy sensation, tearing, widespread eye redness, and often sensitivity to light. They usually do not cause pain or changes in vision. § Corneal disorders usually cause pain (particularly when the eyes are exposed to light), tearing, and sometimes impaired vision. | ||
