Introduction
A corneal ulcer is an open sore or tissue breakdown on the cornea—the clear front window of the eye. It can follow infection (bacterial, viral, fungal, or parasitic), contact-lens misuse, injury, dry eye, or other surface damage. Pain, redness, light sensitivity, tearing or discharge, and blurred vision are common.
In many communities, contact-lens wear, dusty work, chemical or wood/metal exposure, and delayed eye care raise risk. Treating “red eye” with ordinary drops while an ulcer advances can cost vision; ulcers can scar the cornea or, in severe cases, perforate it.
Not all ulcers behave the same: bacterial ulcers often worsen quickly; herpes virus can recur; fungal ulcers may progress slowly but stubbornly; contact-lens–related infections are especially dangerous. Fast diagnosis and targeted treatment protect sight.
This page is general health education, not a personal eye diagnosis. Severe eye pain, sudden vision loss, or redness and pain while wearing contacts need urgent ophthalmology care.
Overview
The cornea must stay clear for light to reach the retina. When the epithelium breaks and infection or inflammation reaches the stroma, pain, haze, and scarring risk rise. This is not ordinary conjunctivitis—corneal tissue injury is involved.
Contact-lens–related keratitis and ulceration are among the more preventable causes worldwide. Sleeping in lenses, using tap or unclean solution, and ignoring trauma after eye injury commonly contribute.
Risk factors include contact lenses, eye trauma, dry eye, diabetes, immunosuppression, prior herpes, and inappropriate steroid eye drops. Children and older adults may need adjusted formulations and closer monitoring.
- Open sore or tissue loss on the corneal surface—can be an eye emergency
- Causes: bacteria, viruses, fungi, parasites, lenses, trauma, dry eye
- Symptoms: sharp pain, redness, discharge, photophobia, blurred vision
- Diagnosis: slit-lamp exam plus fluorescein stain; culture when needed
- Treatment is cause-specific—antibiotic, antiviral, or antifungal therapy
- Delay raises risk of scar, perforation, and permanent vision loss
- Prevention: safe lens hygiene, eye protection, timely specialist review
What happens in the body
Intact corneal epithelium is a barrier to microbes. Trauma, lens-related hypoxia, or dryness breaches that barrier so organisms and inflammatory cells enter the stroma, destroy tissue, and cloud clarity—that process is ulceration.
Bacterial infection can spread rapidly; herpes simplex may hide in nerves and recur; fungi often deepen slowly. Unsupervised steroid drops can weaken local defence and worsen infection. Severe thinning can lead to perforation.
- Epithelial break → microbes/inflammation enter stroma
- Tissue necrosis plus inflammation = pain and loss of transparency
- Contact lenses: hypoxia and biofilm increase infection risk
- Herpes: neuronal latency and recurrent ulcers
- Severe cases: perforation needing urgent surgical care
Signs and symptoms
Severity varies. The list below covers common possibilities—not everyone has every sign:
- Sharp or intense pain in the affected eye
- Redness and a swollen appearance
- Excess tearing or pus-like discharge
- Blurred or distorted vision
- Photophobia (painful sensitivity to light)
- Eyelid swelling
- Foreign-body sensation
- Difficulty keeping the eye open or blinking
- A white or grey spot visible on the cornea
- Sudden drop in vision
- Headache or pressure around the eye
- Inability to tolerate contact lenses
- Severe burning or pain on waking
Causes and risk factors
Infection and mechanical injury drive most cases. Factors below often combine:
- Bacterial infection (often after contact-lens wear or trauma)
- Viral infection—especially herpes simplex
- Fungal or Acanthamoeba infection (lenses or contaminated water)
- Poor contact-lens hygiene or sleeping in lenses
- Eye injury, dust, wood/metal particles, or chemical splash
- Dry eye, blepharitis, or chronic ocular-surface inflammation
- Autoimmune disease or weakened immunity
- Inappropriate steroid eye-drop use
- Diabetes and slower corneal healing with age
Diagnosis and evaluation
An eye specialist confirms the diagnosis with history, slit-lamp exam, and tests as needed:
- Detailed history: lenses, trauma, prior herpes, medication use
- Slit-lamp examination of the cornea and anterior segment
- Fluorescein staining to highlight epithelial defects and ulcers
- Scraping or culture from the ulcer to identify the organism
- Imaging such as corneal topography in selected cases
- Differentiation from conjunctivitis, non-ulcerative keratitis, and abrasion
- Blood tests only when systemic disease is suspected
Treatment and management
Treatment depends on cause and severity. Do not start steroid drops on your own:
- Bacterial: frequent topical antibiotics; oral agents in severe disease
- Viral: antiviral drops or oral therapy (especially herpes)
- Fungal: specific antifungals—courses may be prolonged
- Cautious steroids for inflammation only under specialist supervision
- Stop contact lenses during treatment; avoid rubbing the eye
- Cycloplegic drops when prescribed to ease pain and ciliary spasm
- Surgery, tissue glue, or amniotic membrane if healing fails or perforation threatens
- Corneal transplant considered for dense scar or opacity after infection is controlled
- Vitamins A/C/E and omega-3 may support healing as adjuncts—not replacements for antimicrobial care
Prevention, self-care, and lifestyle
Not every condition is fully preventable, but the steps below may lower risk or recurrence:
- Wash hands with soap before handling contact lenses
- Use only recommended lens solution—never tap, river, or pond water
- Do not sleep in lenses unless specifically advised
- Wear protective eyewear for work, DIY, and sports
- After chemical exposure or trauma, irrigate promptly and seek specialist care
- Treat dry eye with lubricants and regular review
- If you have a herpes or recurrent infection history, plan early review at first symptoms
Possible complications
Delay, missed care, or unsafe self-medication can raise the chance of complications in some cases:
- Corneal scar and permanent blurred vision
- Corneal perforation needing emergency surgery
- Infection spreading inside the eye (endophthalmitis risk)
- Chronic pain or recurrent ulcers
- Irregular astigmatism poorly corrected by glasses
- Rare but real risk of severe vision loss or loss of the eye
- Delayed care increasing need for transplant
When to see a doctor or seek emergency care
Seek prompt medical advice or emergency care if any of the following apply—it is safer not to wait and see:
- Worsening severe eye pain
- Sudden vision loss or inability to see from one eye
- Redness, pain, or discharge while wearing contacts
- Intolerable light sensitivity, pus, or marked swelling
- No improvement within 24–48 hours of home remedies
- Any symptoms after injury or chemical exposure
- New eye problems with diabetes or weak immunity
Living with the condition
Use prescribed drops on schedule; do not rub the eye; avoid swimming and dusty environments until cleared. Soft lighting and sunglasses outdoors can ease photophobia.
Return to contact lenses only after ophthalmology clearance. Discard old cases and solutions and restart a strict hygiene routine.
If ulcers have recurred before, recognise early warning signs and keep follow-up appointments. Anxiety is common—share the plan with family for practical support.
Frequently asked questions
What are the main symptoms of a corneal ulcer?
Severe pain, redness, tearing or discharge, blurred vision, light sensitivity, and eyelid swelling. Seek care urgently for intense pain or vision loss.
How is a corneal ulcer diagnosed?
Through slit-lamp examination, fluorescein staining, and, when needed, culture of material from the ulcer to identify the microbe.
What causes corneal ulcers?
Infections (bacterial, viral, fungal), improper contact-lens use, trauma, dry eye, and sometimes autoimmune disease.
How are corneal ulcers treated?
Cause-specific antibiotics, antivirals, or antifungals. Severe or non-healing ulcers may need surgery or transplant after infection control.
Can a corneal ulcer permanently damage vision?
Yes—delay can leave scar or perforation with lasting vision loss. Early treatment often leads to much better outcomes.
How can I reduce risk?
Follow contact-lens hygiene, wear protective eyewear, avoid rubbing injured eyes, and see an eye specialist promptly if symptoms start.
Important caution
This article is for general education only and is not a substitute for personal ophthalmic care.
Corneal ulcers can worsen quickly—do not delay when pain or vision changes.
Safe hygiene and timely specialist treatment are the most effective ways to protect sight.