How should I assess a patient with red eye to determine if they require urgent referral to an ophthalmologist?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Assess a patient presenting with a red eye by first identifying any signs or symptoms suggestive of a serious, sight-threatening cause, such as acute glaucoma, corneal laceration, corneal foreign body that cannot be removed in primary care, contact lens-related ulcer, corneal ulcer, endophthalmitis, intraocular foreign body, neonatal conjunctivitis, trauma, or chemical injury. Immediate referral to the emergency eye service is indicated for these conditions .

Look for features indicating a need for urgent referral within 24 hours, such as suspected anterior uveitis, scleritis, or if the diagnosis is unclear following clinical assessment .

Refer people urgently (within 24 hours) to the local eye clinic if they have suspected: anterior uveitis or scleritis .

If the diagnosis is uncertain or the clinical assessment suggests a serious or sight-threatening cause, seek ophthalmological advice promptly .

For conditions not requiring urgent referral, manage appropriately in primary care, but always consider red flag signs that warrant urgent assessment .

Educational content only. Always verify information and use clinical judgement.