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Eye Redness

By

Christopher J. Brady

, MD, Wilmer Eye Institute, Retina Division, Johns Hopkins University School of Medicine

Last full review/revision Jun 2021| Content last modified Jun 2021
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Eye redness refers to a red appearance of the normally white part of the eye. The eye looks red or bloodshot because blood vessels on the surface of the eye widen (dilate), bringing extra blood into the eye. Pink eye 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 Infectious Conjunctivitis typically refers to eye redness caused by a specific viral infection.

Blood vessels can dilate as a result of

  • Infection

  • Allergy

  • Inflammation caused by something other than an infection

  • Elevated pressure inside the eye, typically caused by sudden, closed-angle glaucoma, in which fluid pressure increases in the front chamber of the eye

Several parts of the eye may be affected, most commonly the conjunctiva (the thin membrane that lines the eyelid and covers the front of the eye), but also the iris (the colored part of the eye), the sclera (the tough white fiber layer covering the eye), and the episclera (the connective tissue layer between the sclera and the conjunctiva).

An Inside Look at the Eye

An Inside Look at the Eye

Rarely is eye redness the only eye symptom. People may have tearing, itching, the feeling that a foreign object is in the eye (foreign body sensation), sensitivity to light, pain, or even changes in vision. Sometimes people have symptoms that affect other areas of the body, such as a runny nose or cough, or nausea and vomiting.

Causes

Many disorders can cause eye redness. Some are emergencies, but others are mild and go away without treatment. The degree of redness does not indicate the seriousness of the disorder. The presence of eye pain or vision problems is more likely to suggest a serious cause.

The most common causes of eye redness are

Scratches of the cornea 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 (the clear layer in front of the iris and pupil) and foreign objects in the eye 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 are also common causes of eye redness. In these cases, however, the person is more likely to consider the problem to be an eye injury, eye pain, or both. Corneal scratches may be caused by contact lenses or by foreign objects or tiny particles trapped under the eyelid. Occasionally, very dry air can cause some eye redness and irritation.

Serious causes of eye redness are much less common. They include corneal ulcers Corneal Ulcer A corneal ulcer is an eye infection that causes an open sore on the cornea (the clear layer in front of the iris and pupil). Contact lenses, injuries, disorders, drugs, and nutritional deficiencies... read more Corneal Ulcer , 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 Herpes Simplex Keratitis (herpes infection in the cornea), 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 Herpes Zoster Ophthalmicus (shingles in or around the eye), acute closed-angle glaucoma Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage (often, but not always, associated with increased eye pressure) that can lead to irreversible loss of vision... read more , 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 , and 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 (a deep, painful inflammation of the sclera).

Table
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Evaluation

Not every case of eye redness requires evaluation by a doctor. The following information can help people decide when to see a doctor and to know what to expect during an evaluation. In most cases, people with eye redness can be evaluated by a general health care practitioner rather than an ophthalmologist (a medical doctor who specializes in the evaluation and treatment—surgical and nonsurgical—of eye disorders).

Warning signs

In people with eye redness, certain symptoms and characteristics are cause for concern. They include

  • Sudden, severe pain and vomiting

  • Rash on the face, particularly around the eyes or on the tip of the nose

  • Decreased sharpness of vision (visual acuity)

  • An open sore on the cornea

When to see a doctor

Deep eye pain Eye Pain Eye pain may be severe and seem sharp, aching, or throbbing, or people may feel only mild irritation of the eye surface or the sensation of a foreign object in the eye (foreign body sensation)... read more should be distinguished from irritation. People who have warning signs, particularly deep pain or a change in vision, should see a doctor right away. If no warning signs are present, it is safe to wait a couple of days or so, but people may want to see a doctor sooner so that they can start treatment quickly.

What the doctor does

Doctors first ask questions about the person's symptoms and medical history and then do a physical examination. What they find during the history and physical examination often suggests a cause of eye redness and the tests that may need to be done (see table Some Causes and Features of Eye Redness Some Causes and Features of Eye Redness Eye redness refers to a red appearance of the normally white part of the eye. The eye looks red or bloodshot because blood vessels on the surface of the eye widen (dilate), bringing extra blood... read more ).

Doctors ask

  • How long redness has been present

  • Whether redness has occurred before

  • Whether there is pain or itching

  • Whether there is discharge or the eyes are tearing

  • Whether there is a change in vision

  • Whether there has been an eye injury

  • Whether the person wears contact lenses and whether they have been overused

  • Whether the person has been exposed to substances (such as dust or eye drops) that could irritate the eyes

  • Whether there are other symptoms (such as headache, halos around lights, runny nose, cough, or sore throat)

  • Whether the person has allergies

Pain together with nausea or vomiting or halos around lights is a potentially serious combination of symptoms. These symptoms often occur in acute closed-angle glaucoma Types of glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage (often, but not always, associated with increased eye pressure) that can lead to irreversible loss of vision... read more . Pain and sensitivity to light may indicate a disorder of the cornea, such as a scratch or a foreign object. An absence of pain and sensitivity to light may indicate a disorder of the conjunctiva.

During the physical examination, doctors examine the head and neck for signs of disorders that may cause eye redness, such as runny nose and cough that may indicate an upper respiratory infection or allergy or a rash that may indicate shingles (herpes zoster infection).

The eye examination is the most important part of the physical examination. Doctors check the person's eye and the area around the eye for injuries or swelling. They check the person's vision (with glasses or contacts if the person wears them), pupil size and response to a light, and eye movement.

If pain develops in the affected eye (particularly if it is shut at this time) when a light is shined in the unaffected eye, the problem may be 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 or a corneal disorder. The use of an anesthetic makes the examination easier, and the person's response to the anesthetic may be a clue to the diagnosis. Anesthetic eye drops do not relieve pain that is caused by glaucoma, uveitis, or scleritis.

Testing

Testing is usually unnecessary.

If doctors suspect a viral infection (herpes simplex virus or varicella-zoster virus), they may take samples of discharge or blister fluid to send to the laboratory. The sample is placed in a culture medium (a substance that allows bacteria or viruses to grow). Samples for culture may also be taken when the person has a corneal ulcer so doctors can give antibiotics that are most likely to be effective. Gonioscopy (use of a special lens to examine the drainage channels in the eye) is done in people with glaucoma. Sometimes people with uveitis are tested for autoimmune disorders, especially if there is no obvious cause (such as an injury) for the uveitis.

Treatment

The cause is treated. Eye redness itself does not require treatment. It usually clears up on its own as the cause resolves (for example, a few days for infectious conjunctivitis or a couple of weeks for subconjunctival hemorrhage). Cool washcloths or artificial tears can be applied if any itching is particularly bothersome. Eye drops that aim to eliminate redness (available over-the-counter) are not recommended.

Key Points

  • Usually, eye redness is caused by conjunctivitis.

  • Pain, a rash around the eye or nose, and changes in vision suggest a potentially serious cause.

Drugs Mentioned In This Article

Generic Name Select Brand Names
NEO-FRADIN
COUMADIN
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