Initial Examination

A comprehensive account of examination of the eye is included in the session on the initial assessment of the eye.

The examination of any patient presenting with a red eye must begin with measurement of the visual acuity.

Examine the face for a dermatomal rash (seen in herpes zoster), other herpetic lesions and lymphadenopathy in the pre-auricular or submandibular regions. External examination of the eye will identify pathology related to the eyelids and tear duct.

Inspect the palpebral fissure in all directions of gaze to identify the nature and extent of redness.

 Table 1  Nature and extent of redness in the eye
Extent of redness Possible indication

Generalised/peripheral conjunctival injection (prominence of blood vessels)


Localised injection


Perilimbal injection

Corneal, anterior chamber or anterior uveal problem

Blood in the subconjunctival space

A subconjunctival haemorrhage

Learning bite

The distribution of redness in the eye is a useful sign, in some cases pointing directly to the correct diagnosis.

Inspection may also reveal:

  • Conjunctival oedema (chemosis)
  • Opacification (clouding) of the cornea
  • Pus in the anterior chamber (hypopyon)