Conditions · Ophthalmology and ENT
Corneal abrasion and ocular foreign body !
A scratch on the clear front of the eye, or a small particle stuck to it. It hurts a lot, but most heal in a few days with proper care.
Updated 2026-11-01
Structures involved
Tap one to see what it is and open it in 3D.
Why it happens
- Tissue repair: regeneration or scar; labile, stable and permanent cells
- The eye wall: cornea, sclera, uvea and lens
- Stem cells and tissue renewal: labile, stable and permanent tissues
What it is
Loss of part of the corneal epithelium from a scratch (fingernail, branch, contact lens) or from a small foreign body on the cornea or under the eyelid. It is one of the most common eye problems seen in emergency rooms.
Who gets it
Very common at all ages, especially in young adults, workers who grind, weld or drill metal, farm workers and contact lens wearers. In agricultural areas of Colombia, injuries with plant material raise the risk of fungal keratitis.
Causes
- Direct scratch: fingernail, branch or leaf, makeup brush, paper
- Metal, wood, glass or sand particles, often from grinding, hammering or wind
- Contact lenses worn too long or inserted badly
- Rubbing the eye with a particle under the upper eyelid
Risk factors
- Work with metal, wood or power tools without safety glasses
- Agricultural work and outdoor activities in windy conditions
- Contact lens use, especially overnight
- Young children and contact sports
Pathophysiology
The cornea is the most densely innervated tissue in the body, so even a small epithelial defect causes severe pain, tearing and spasm of the eyelids. Healthy epithelium slides over and covers small defects within one to three days. A retained foreign body, especially an iron particle, leaves a rust ring and keeps the surface open to infection; organic material and contact lenses favour bacterial (including Pseudomonas) or fungal keratitis.
Symptoms and signs
- Sharp eye pain and foreign-body sensation, worse with blinking
- Tearing and red eye
- Light sensitivity (photophobia)
- Blurred vision if the defect is central
- Spasm of the eyelids (blepharospasm)
Diagnosis
- Clinical
- Visual acuity first, then examination with a topical anaesthetic, eversion of the upper eyelid, and fluorescein staining under cobalt-blue light, which shows the defect in green. Vertical linear scratches suggest a particle under the upper eyelid.
- Tests
- Usually none. Culture of a corneal scraping if there is an infiltrate or ulcer.
- Imaging
- Slit-lamp examination. CT of the orbit when an intraocular metallic foreign body is suspected (MRI is avoided if metal may be present).
Differential diagnosis
- Infectious keratitis or corneal ulcer
- Open globe injury or intraocular foreign body
- Chemical eye injury
- Herpes simplex keratitis (branching dendritic lesion)
- Acute angle-closure glaucoma, conjunctivitis and anterior uveitis as other causes of a painful red eye
Goal of treatment
Remove any foreign body, relieve pain, prevent infection while the epithelium heals, and recognise the injuries that need an ophthalmologist (open globe, infection, deep or retained particles).
Treatment
- Procedure
- Removal of a superficial foreign body with irrigation, a moist cotton swab or a fine needle under the slit lamp after topical anaesthesia; a rust ring may be removed with a burr by trained staff.
- Medical
- Topical antibiotic drops or ointment until healing (with Pseudomonas coverage in contact lens wearers), oral analgesics and sometimes cycloplegic drops for pain.
- Conservative
- Patching is generally not recommended; contact lenses are left out until the eye heals. Topical anaesthetics are not given for home use because they slow healing and mask complications.
- Follow-up
- Review within 24–48 hours for large, central or contaminated abrasions; nursing teaching covers drop technique, warning signs and protective eyewear.
Drugs for this condition
Complications
- Bacterial or fungal keratitis and corneal ulcer
- Recurrent corneal erosion syndrome (pain on waking, months later)
- Corneal scar affecting vision
- Missed intraocular foreign body with endophthalmitis or siderosis
Prognosis
Most simple abrasions heal within one to three days without sequelae. The outlook is worse with infection, a central scar or a penetrating injury.
Prevention
- Safety glasses when grinding, hammering, welding or using power tools
- Good contact lens hygiene and no overnight wear unless approved
- Eye protection in sports and agricultural work
Test yourself
Think of the answer, then tap the question to see it.
Which test shows a corneal abrasion, and how does it look?
Fluorescein staining under cobalt-blue light: the area without epithelium stains green.
What do vertical linear scratches on the cornea suggest?
A foreign body trapped under the upper eyelid, found by everting it.
Which organism is a special concern in corneal abrasions in contact lens wearers?
Pseudomonas aeruginosa, so antibiotics that cover it are used and patching is avoided.
Why are topical anaesthetics not given for home use after a corneal abrasion?
Repeated use delays epithelial healing, can damage the cornea and hides worsening pain from infection.
Which imaging is chosen to look for a metallic intraocular foreign body?
CT of the orbit; MRI is avoided because a ferromagnetic fragment can move and injure the eye.
Related conditions
- Chemical eye injury
- Keratitis and corneal ulcer
- Conjunctivitis
- Endophthalmitis
- Uveitis
- Acute angle-closure glaucoma
Educational information, not medical advice. For any symptom, see a health professional.
Sources: Corneal injury: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Eye emergencies: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.
