Keratitis

Keratitis is inflammation of the cornea, the clear dome at the front of the eye. It may result from infection, contact lens misuse, trauma, dry eye, or surface disease, and it can threaten vision if treatment is delayed. ^[1][2]

Because eye redness is common and often benign, keratitis can initially be underestimated. However, a painful red eye with light sensitivity, blurred vision, or contact lens use deserves careful and often urgent assessment. ^[1][3]

What is keratitis?

Keratitis refers to inflammation affecting the cornea. The condition may be infectious or noninfectious, and its severity ranges from mild surface irritation to an ulcerative process that can scar the cornea. ^[1][2]

The cornea must remain clear to preserve vision, which is why even a small area of inflammation can be clinically important. ^[1][3]

What are the symptoms of keratitis?

Typical symptoms include eye redness, pain, tearing, blurred vision, light sensitivity, foreign-body sensation, and difficulty keeping the eye open. Contact lens wearers may describe rapidly worsening discomfort or reduced vision. ^[1][2][4]

Discharge may occur, but the overall pattern matters more than any single symptom. Severe pain or vision change should never be dismissed as “just irritation.” ^[1][3]

What causes keratitis and what are the risk factors?

Important causes include bacterial, viral, fungal, and parasitic infection; corneal injury; dry eye; eyelid disorders; and contact lens problems such as overnight wear or poor hygiene. ^[1][2]

Risk rises in people who sleep in contact lenses, use lenses while swimming, have ocular surface disease, or delay care after an eye injury. ^[1][3]

How is it diagnosed?

Diagnosis relies on symptom history, slit-lamp examination, and in selected cases corneal staining, cultures, or other targeted tests. The key question is often not only whether the cornea is inflamed, but whether infection is present and whether ulceration has developed. ^[1][2]

Because the cornea can deteriorate quickly, same-day or urgent assessment may be appropriate depending on the clinical picture. ^[1][3]

How is keratitis treated?

Treatment depends on the cause. Infectious keratitis may require antimicrobial therapy directed to the likely organism, while noninfectious forms may require lubrication, treatment of eyelid or surface disease, or other specialist-guided care. ^[1][2]

The wrong medication can worsen the condition, so self-starting old antibiotic or steroid drops is not a safe routine response to a painful red eye. ^[1][4]

When is urgent evaluation needed, and what helps prevention?

Urgent eye evaluation is warranted for painful red eye, light sensitivity, blurred vision, contact lens-related symptoms, or eye trauma. Delaying care may increase the risk of corneal scarring and vision loss. ^[1][2]

Prevention includes good lens hygiene, avoiding sleeping in lenses unless specifically approved, not exposing lenses to water, and seeking care early when the eye becomes red or painful. ^[1][3]

FAQ

Is keratitis contagious?

Some infectious causes can be transmissible, but keratitis itself is not a single contagious disease. The answer depends on the underlying cause. ^[1][3]

What should I do if my eye becomes red while I wear contact lenses?

Remove the lenses and seek prompt eye assessment, especially if there is pain, light sensitivity, or blurred vision. Continuing lens wear can worsen the problem. ^[1][2]

Can keratitis cause blindness?

Severe or untreated keratitis can lead to corneal scarring and significant vision loss, which is why timely treatment matters. ^[1][4]

Is it correct to start antibiotic eye drops at home?

Not without appropriate guidance. A painful red eye may have different causes, and incorrect treatment can delay diagnosis or worsen some forms of keratitis. ^[1][3]

How long does keratitis take to heal?

Recovery time varies with the cause and severity. Mild noninfectious cases may settle relatively quickly, while infectious keratitis can require closer and longer treatment. ^[1][2]