Photokeratitis (Ultraviolet [UV] burn, Arc eye, Snow Blindness)

The CMGs are guidelines on the diagnosis and management of a range of common and rare, but important, eye conditions that present with varying frequency in primary and first contact care.

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Exposure to UVB (290 to 320nm) or UVC (100 to 290nm)
Sources: welding arcs, sun (including reflection from snow or water), tanning lamps, therapeutic high intensity UV (for skin conditions or seasonal affective disorder), germicidal UV lamps, other sources of UVB or UVC
Absorption of radiation by corneal epithelium causing punctate erosions

Predisposing factors

Lack of suitable eye protection


Delay of 6-12 hours between exposure and onset of symptoms is usual; however, latency varies inversely with exposure dose and can be as short as 1 hour

Mild cases:

  • irritation and foreign body sensation

Severe cases:

  • pain
  • redness
  • photophobia
  • blepharospasm
  • lacrimation
  • blurring of vision


Bilateral (if unilateral, suspect corneal or subtarsal foreign body)
Lid chemosis and redness
Conjunctival hyperaemia
Punctate staining of corneal epithelium with fluorescein (may be coalescent)
Mild transitory visual loss
Associated skin burns from UV exposure

Differential diagnosis

Acute viral keratoconjunctivitis
Contact or toxic keratitis
Contact lens overwear
Dry eye
Foreign body

Management by optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

Non pharmacological

Advise against continuing exposure
Reassure patient that

  • damage is transitory
  • symptoms will be gone within 24 to 48 hours (mild photophobia and blurring may persist for a week or longer)

Cold compresses, sunglasses for symptomatic relief
Advise rest with eyes closed
Review following day (corneal epithelium should have largely healed)
Advise patient to return/seek further help if symptoms persist
Advise patient on future eye protection
(GRADE*: Level of evidence=low, Strength of recommendation=strong)


Local anaesthetic (benoxinate or proxymetacaine) should be used only if required to aid examination, and not for pain relief
Drops: tear supplements (preferably unpreserved) for symptomatic relief
Ointment: unmedicated (to ease discomfort through lubrication)
Oral analgesic for pain relief (e.g. ibuprofen, paracetamol)
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Antibiotic (e.g. gutt. chloramphenicol 0.5%) as prophylaxis against infection, if risk high (e.g. large epithelial defect)
Cycloplegic (short acting: e.g. gutt. cyclopentolate 1%) to relieve pain of ciliary spasm
(GRADE*: Level of evidence=low, Strength of recommendation=weak)

Management category

B3: Management to resolution by optometrist

Possible management by ophthalmologist

Not normally required

Evidence base

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

Sources of evidence

Cullen AP. Photokeratitis and other phototoxic effects on the cornea and conjunctiva. Int J Toxicol. 2002;21:455-64

DynaMed Plus. Photokeratitis (updated 2018)

Protective eyewear: A reference guide for ABDO members. 2014.

Remé CE, Rol P, Grothmann K, Kaase H, Terman M. Bright light therapy in focus: lamp emission spectra and ocular safety. Technol Health Care. 1996;4(4):403-13

Plain language summary

This condition is also known as Arc Eye and Snow Blindness. It is caused when the eyes are exposed to too much ultraviolet (UV) light. After a delay of 6 to 12 hours following exposure to arc welding, sun lamps or other sources of UV light, the eyes become red, painful, watery and unduly sensitive to light. The vision may become blurred and the eyelids may be red and swollen. These symptoms are caused by temporary damage to the cells on the surface of the eye. Fortunately the condition gets better by itself and there is usually no permanent damage. Eye drops can be prescribed or purchased to make the eyes more comfortable while they recover. Pain relief tablets may be needed also.

Photokeratitis (Ultraviolet [UV] burn, Arc eye, Snow Blindness)
Version 12
Date of search 30.06.19
Date of revision 12.07.19
Date of publication 23.04.21
Date for review 29.06.21
© College of Optometrists 

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