The corneal reflex, or blink reflex, is a protective response where both eyes blink when the cornea is lightly touched. It assesses trigeminal and facial nerve function.
How it is tested
Care is taken to minimise discomfort.
- A fine wisp of cotton or gentle air puff is directed toward the cornea
- Normal response is an immediate blink of both eyelids
- Absence or asymmetry suggests sensory loss in the ophthalmic branch of the trigeminal nerve or motor dysfunction of the facial nerve
- Can also be reduced in contact lens wearers or after refractive surgery
Clinical relevance
The reflex helps protect the eye and localise neurological lesions.
- Impairment increases risk of exposure keratopathy and corneal ulceration
- Important in assessing coma, brainstem integrity, and facial palsy
- Patients with absent reflex need lubricants and sometimes lid closure procedures
- Findings are interpreted alongside other cranial nerve tests
