Kornealrefleksion

Kornealrefleksion, also known as the corneal reflex or blink reflex, is an involuntary reflex that causes blinking when the cornea is stimulated. This reflex is crucial for protecting the eye from potential harm. The stimulus can be a light touch to the cornea, such as from a foreign object, a puff of air, or even a sudden bright light.

The pathway of the corneal reflex involves several cranial nerves. Sensory information from the cornea is carried by the ophthalmic division of the trigeminal nerve (cranial nerve V) to the brainstem. Motor commands to close the eyelids are then sent via the facial nerve (cranial nerve VII) to the orbicularis oculi muscles. This rapid sequence of events results in the forceful closure of both eyelids.

Testing the corneal reflex is a common part of a neurological examination. A healthcare professional will typically use a fine wisp of cotton or a sterile cotton swab to gently touch the cornea. A normal response is for the patient to blink both eyes. The absence or asymmetry of this reflex can indicate damage to the trigeminal nerve, facial nerve, or the brainstem pathways involved. It is important to note that the reflex should be elicited gently to avoid causing discomfort or injury to the cornea. The corneal reflex is distinct from the pupillary light reflex, which controls the size of the pupil in response to light intensity.