07/10/2025
Here are the main causes of keratitis (inflammation of the cornea):
1. Infectious Causes
Bacterial keratitis → Often linked to contact lens overuse or poor lens hygiene. Common bacteria: Pseudomonas aeruginosa, Staphylococcus aureus.
Viral keratitis → Usually due to Herpes simplex virus (HSV) or Herpes zoster virus (shingles).
Fungal keratitis → Caused by fungi like Fusarium or Candida; usually after eye injury with plant/organic matter or in people with weakened immunity.
Parasitic keratitis → Acanthamoeba keratitis, often associated with improper contact lens care or swimming with lenses.
2. Non-Infectious Causes
Eye injury / trauma → Scratches or foreign bodies on cornea.
Dry eyes → Severe dryness can cause irritation and inflammation.
Allergic reaction → Allergic conjunctivitis may extend to cornea.
Exposure keratitis → Incomplete eyelid closure (e.g., Bell’s palsy) leading to cornea dryness.
Contact lens misuse → Wearing lenses too long, poor cleaning, or sleeping with them.
UV light exposure → Excessive sunlight, tanning beds, or welding ("welder’s flash").
Autoimmune diseases → Conditions like rheumatoid arthritis or lupus can cause inflammatory keratitis.
