Corneal (or other superficial ocular) foreign body


Corneal foreign body is one of the most common ophthalmic injuries. Foreign bodies usually affect the superficial cornea, however, can cause a deeper or penetrating injury with scarring and potential visual impairment.

Patient often gives history of foreign body entering eye

  • wind blown
  • high velocity (hammering, grinding)
  • DIY and gardening

Predisposing factors

Sex-predominantly male
Lack of suitable eye protection

Symptoms of corneal foreign body

Typically unilateral
Irritation/foreign body sensation/pain
Blurred vision
Red eye

Signs of corneal foreign body

Foreign body adherent to ocular surface
Linear corneal scratches (common in the case of sub-tarsal foreign body)
Corneal rust ring from embedded ferrous foreign body
Surrounding ring of oedema and infiltrate if longstanding
Subconjunctival haemorrhage may be present

Differential diagnosis

History is important

  • high velocity particles – risk of globe penetration
  • metallic (ferrous) – rust ring (haemosiderosis)
  • vegetative – risk of fungal infection

Recurrent erosion syndrome
Sub-tarsal foreign body

Management by optometrist

Practitioners should work within their scope of practice, and where necessary seek further advice or refer the patient elsewhere

Non pharmacological

Rule out multiple particles – cornea, conjunctiva (bulbar, fornix, palpebral); if appropriate double evert lids following instillation of topical anaesthetic (e.g. using a Desmarre's retractor, if available)

  • loose foreign body can be irrigated away with normal saline
  • foreign body on conjunctiva can be removed with a sterile cotton bud
  • assess depth of corneal foreign body (using slit lamp optical section, although anterior segment OCT (AS-OCT) can provide additional information on corneal layers affected and wound status after removal)
  • carry out Seidel test if suspected corneal perforation
  • corneal foreign body may require removal with a sterile hypodermic needle or other disposable instrument. To reduce the risk of corneal penetration, ensure that the needle approaches the cornea tangentially
  • after removal, assess size of remaining epithelial defect so that healing can be monitored


  • VA before and after FB removal
  • globe and adnexae for signs of penetration
  • where there is any suspicion of a penetrating injury, carry out dilated fundus examination
  • examine AC for cells or flare
  • pupil responses

(GRADE*: Level of evidence=low, Strength of recommendation=strong)

For those specifically trained, use of burr or other instrument (e.g. Alger Brush) to remove rust ring

  • if non-disposable instruments are used they must come from a sterile pack
  • When undertaking invasive procedures, optometrists should ensure that appropriate medical malpractice (professional indemnity) insurance and clinical governance arrangements are in place and the College of Optometrists guidance on expanded scope of practice is followed.

(GRADE*: Level of evidence=low, Strength of recommendation=weak) 

Do not pad or patch eye
(GRADE*: Level of evidence=high, Strength of recommendation=strong)

Advise patient to return/seek further help if symptoms persist
Advise patient to wear suitable eye protection in future
(GRADE*: Level of evidence=low, Strength of recommendation=strong)


Remove foreign body under topical anaesthesia (gutt. proxymetacaine 0.5% or gutt. oxybuprocaine 0.4%)
Consider use of ointment (unmedicated or medicated) following removal (as ocular lubrication)
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

If there is a likelihood of infection, consider topical antibiotic prophylaxis (e.g. gutt. chloramphenicol 0.5%)
For large epithelial defects, cycloplegia to prevent pupil spasm (e.g. gutt cyclopentolate 1% twice daily until healed)
(GRADE*: Level of evidence=low, Strength of recommendation=weak)

In the case of contact lens wearers, antibiotic prophylaxis should be with a drug effective against Gram -ve organisms, e.g. a quinolone such as levofloxacin or moxifloxacin, or an aminoglycoside such as gentamicin. Contact lenses should not be worn during the treatment period
(GRADE*: Level of evidence = low, Strength of recommendation = strong)

Systemic analgesia if necessary (e.g. ibuprofen, or paracetamol if contraindicated) 
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Topical NSAID for its analgesic and anti-inflammatory properties, e.g. gutt. diclofenac 0.1%
RCTs do not provide strong evidence to support their use
(GRADE*: Level of evidence=moderate, Strength of recommendation=weak)

Management category

B3: superficial FB: management to resolution, normally no referral
A2: penetration into stroma, or presence of rust ring, may result in scarring and potential visual loss, therefore refer to ophthalmologist as emergency (same day); (but note exception for optometrists specifically trained in rust ring removal)

Possible management in secondary care or local primary/community pathways where available

Additional guidance may be available

Exploration of wound (especially if sub-conjunctival haemorrhage is also present)

Removal of deep foreign body

Use of burr or other instrument to remove rust ring

Ultrasonography if suspected intraocular foreign body

Evidence base

*GRADE: Grading of Recommendations Assessment, Development and Evaluation (See

Sources of evidence

Bhargava M, Bhambhani V, Paul RS. Anterior segment optical coherence tomography characteristics and management of a unique spectrum of foreign bodies in the cornea and anterior chamber. Indian J Ophthalmol. 2022;70(12):4284-4292.

Corneal Abrasions. BMJ Best Evidence 2021

Lim CH, Turner A, Lim BX. Patching for corneal abrasion. Cochrane Database Syst Rev. 2016;7:CD004764

Meek R, Sullivan A, Favilla M, Larmour I, Guastalegname S. Is homatropine 5% effective in reducing pain associated with corneal abrasion when compared with placebo? A randomized controlled trial. Emerg Med Australas. 2010;22(6):507-13

Sun F, Zhou Y, Dong L, QinH. Relationship between the use and type of eye protection and work-related corneal and conjunctival foreign body injuries. Inj Prev. 2020 Dec 22;injuryprev-2020-043958. doi: 10.1136/injuryprev-2020-043958. Online ahead of print.

Uyar E, Sarıbaş F. Evaluating Depth and Width of Corneal Wounds Using Anterior Segment Optical Coherence Tomography After Foreign Body Removal. Semin Ophthalmol. 2022;37(6):774-779.

Wakai A, Lawrenson JG, Lawrenson AL, Wang Y, Brown MD, Quirke M, Ghandour O, McCormick R, Walsh CD, Lang E, Amayem A. Topical nonsteroidal anti-inflammatory drugs for analgesia in traumatic corneal abrasions. Cochrane Database of Systematic Reviews 2017;5:CD009781

Wipperman JL, Dorsch JN. Evaluation and management of corneal abrasions. Am Fam Physician. 2013;87(2):114-20


What is a foreign body?

Small foreign bodies often enter the eye. Usually these are blinked away but sometimes they stick to the surface of the cornea (the clear window of the eye). This is more likely if they enter at high speed, for example when blown in by the wind or when they result from hammering, grinding, other DIY and gardening activities.

How are foreign bodies managed?

If a foreign body sticks to the cornea it can be removed by the optometrist with a delicate instrument after the surface of the eye has been numbed by an anaesthetic drop. If the foreign body is iron-based, it may have quickly rusted on the eye surface, in which case the rust will need to be removed also. If there is a likelihood of infection, antibiotic drops and/or ointment may be prescribed. Patients will be referred to the ophthalmologist (eye doctor) only if the foreign body has penetrated below the surface or is likely to cause corneal scarring.

Corneal (or other superficial ocular) foreign body
Version 17
Date of search 08.06.23
Date of revision 08.08.23
Date of publication 17.10.23
Date for review 07.06.25
© College of Optometrists 

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