Eye infections occur when viruses, bacteria, fungi, or parasites invade the eye and surrounding tissues. Symptoms like redness, swelling, pain, discharge, or blurred vision may signal an infection that needs prompt attention from an eye doctor.
While many eye infections resolve without lasting damage, proper diagnosis helps improve healing time, prevent spread to others, and avoid complications that could affect your vision.
Eye infections can have many causes, and the symptoms often overlap. Eye doctors have specialized equipment and training to identify the underlying cause and provide appropriate treatment. Attempting to self-treat or ignoring symptoms can lead to worsening conditions and potentially sight-threatening complications.
Certain symptoms warrant an immediate visit to an eye doctor. Do not delay care if you notice any of the following warning signs.
Some symptoms may indicate serious conditions that require rapid evaluation to prevent permanent damage.
Certain groups face greater risk from eye infections and should seek care promptly if symptoms develop. These include infants and young children, immunocompromised individuals, and people who recently had eye surgery or trauma.
This is the most common type of infectious conjunctivitis in adults. It usually starts with redness and watery discharge in one eye, then often spreads to the other eye within a few days. Symptoms include itching, a gritty sensation, mild swelling, and sensitivity to light. Many people experience cold or flu symptoms at the same time.
Viral conjunctivitis is highly contagious through direct contact with eye secretions or contaminated surfaces. No specific antiviral treatment exists, so care focuses on comfort measures like artificial tears and cold compresses. Symptoms typically resolve within one to two weeks.
Bacterial conjunctivitis affects the conjunctiva, which is the clear membrane covering the white of the eye and inner eyelids. It causes redness along with thick, yellow or green discharge. Eyelids may stick together, especially upon waking. It accounts for a significant portion of eye infections, particularly in children.
This infection is contagious through close contact. Treatment often involves antibiotic eye drops or ointments. Improvement typically occurs within three to four days of starting treatment, though the full course should be completed.
Fungal infections cause redness, light sensitivity, blurred vision, and severe pain. A visible corneal ulcer may develop. These infections are more common after eye injuries involving plant matter, in contact lens wearers, or after exposure to contaminated water.
Fungal infections are not contagious between people but require prompt medical attention. Treatment involves antifungal medications and may require weeks to months. Severe cases may need surgical intervention.
Allergic conjunctivitis causes itchy, red, watery eyes with swollen eyelids. It results from allergic reactions to pollen, dust mites, pet dander, or other allergens. This is not an infection and is not contagious.
Treatment focuses on avoiding allergens and using antihistamine eye drops or oral antihistamines. Cold compresses can provide relief. Symptoms may persist during periods of allergen exposure.
This parasitic infection causes severe eye pain that seems worse than visible symptoms suggest. Keratitis refers to infection of the cornea, which is the clear front surface of the eye. It starts with redness and discomfort, then progresses to intense pain, blurred vision, and light sensitivity. A ring-shaped corneal ulcer may develop.
Acanthamoeba keratitis is associated with contact lens wear, especially with poor hygiene or exposure to contaminated water sources like swimming pools or hot tubs. Treatment requires long-term anti-parasitic medications, often for three to twelve months. Severe cases might require corneal transplant.
This condition begins with tingling or burning on the forehead or eyelids, followed by pain, eye redness, and a skin rash or blisters. It results from reactivation of the chickenpox virus affecting nerves near the eye.
It is contagious to people who have not had chickenpox or the vaccine. Oral antiviral medications work best when started within 72 hours of rash onset. Treatment typically lasts seven to ten days, though additional care may continue for weeks based on severity.
Cellulitis causes redness and swelling around the eyelids, along with tenderness, fever, and general discomfort. As it progresses, pain and swelling increase, and reduced eye movement may occur in orbital cellulitis.
This bacterial infection can result from sinus infections, trauma, or spread from nearby structures. Orbital cellulitis is a medical emergency due to the risk of serious complications. Hospitalization and intravenous antibiotics are often required.
This infection inside the eye causes severe pain, decreased or blurred vision, redness, and eyelid swelling. It typically follows eye surgery, trauma, or systemic infections.
Endophthalmitis is an ocular emergency. Treatment involves urgent antibiotic injections into the eye and possible surgery. Delay can result in permanent vision loss.
Bacterial keratitis begins with eye redness and mild irritation, then progresses to severe pain, discharge, blurred vision, and light sensitivity. A corneal ulcer may become visible. It is especially common in contact lens wearers who do not follow proper hygiene practices.
Treatment requires high-concentration topical antibiotics, often applied hourly at first. Duration spans several weeks depending on severity. Urgent care is required to prevent complications.
Viral keratitis, usually caused by herpes simplex virus, causes eye pain, redness, tearing, blurred vision, and light sensitivity. Characteristic dendritic (branching) ulcers may be visible on the cornea.
Treatment involves antiviral medications and continues for two to three weeks or until the ulcer heals. Immediate evaluation by an eye doctor is necessary to improve outcomes.
Any corneal infection, whether bacterial, viral, fungal, or parasitic, can threaten vision if not treated promptly. Risk factors include contact lens wear, corneal abrasions, eye trauma, and immunosuppression.
Treatment depends on the cause and typically involves intensive eye drop therapy. Regular follow-up ensures the infection is responding appropriately.
Contact lens users face higher risk for certain infections, particularly bacterial and parasitic keratitis. Improper lens hygiene, sleeping in contacts, and exposure to water while wearing lenses can introduce harmful microbes to the cornea.
These infections can progress rapidly, causing severe pain, vision loss, and blindness if not treated promptly. Following strict cleaning and replacement protocols and avoiding risky behaviors like swimming in contacts are essential.
Eye infections are especially concerning in young children who cannot effectively describe their symptoms or stop themselves from touching their eyes. Bacterial and viral conjunctivitis spread easily in daycares and schools.
Parents should watch for signs of eye redness, discharge, pain, or light sensitivity and seek prompt evaluation through pediatric eye care. Timely treatment is essential to prevent complications in this vulnerable group.
Several factors increase susceptibility to eye infections.
Proper diagnosis requires a thorough evaluation. An eye doctor will take a detailed medical history, examine the eyes with a slit lamp microscope, evaluate the cornea, tear film, and eyelids, and test visual acuity and eye pressure.
When needed, the doctor may culture discharge samples to identify the infectious agent, perform corneal scrapings, or use special dyes and imaging to check for damage.
Treatment depends on the specific type of infection diagnosed. Options may include the following.
Close monitoring ensures the infection improves as expected. In resistant or severe cases, treatment may require multiple medications or prolonged therapy. Follow-up visits allow the doctor to adjust treatment based on response.
Eye infections can progress rapidly and lead to serious problems.
Simple habits can significantly reduce your risk of developing an eye infection.
If you have an eye infection, take steps to promote healing and prevent spread.
While mild symptoms may improve on their own, we generally do not recommend self-treating eye infections. Different types of infections require different treatments, and using the wrong approach can delay healing or cause harm. For example, antibiotic drops will not help a viral infection, and steroid drops used without proper diagnosis can worsen certain conditions.
For viral conjunctivitis, it is best to stay home until symptoms improve, typically five to seven days. For bacterial conjunctivitis, you can usually return 24 hours after starting antibiotic treatment if symptoms are improving. Fungal and parasitic infections are not contagious between people, so time off depends on how you feel rather than transmissibility.
No. You should stop wearing contact lenses immediately if you develop signs of an eye infection. Continue to avoid contacts until your eye doctor confirms the infection has fully resolved. Discard any disposable lenses or lens cases used during or just before the infection.
Recurrent infections may indicate an underlying issue such as chronic dry eye, blepharitis, or an immune system condition. Some viral infections like herpes can reactivate periodically. If you experience repeated infections, a comprehensive evaluation can help identify contributing factors and develop a prevention plan. You may benefit from completing our dry eye quiz to assess your symptoms.
Conjunctivitis affects the conjunctiva and typically causes redness and discharge but rarely threatens vision. Keratitis affects the cornea and is more serious because the cornea is essential for focusing light, and damage can cause scarring and permanent vision loss.
Go to the emergency room if you experience sudden severe vision loss, intense eye pain that does not respond to over-the-counter pain relievers, or symptoms following eye injury or surgery. For milder symptoms like redness, irritation, or mild discharge without severe pain or vision changes, scheduling an appointment within a day or two is usually appropriate.
