What is the corneal light reflex, and how is it examined?

The corneal light reflex refers to how light is reflected from the corneas of the eyes. In proper eye alignment (also called ocular alignment), a light reflection is equally centered on both pupils — if it is unequal, an eye misalignment disorder like strabismus or amblyopia (lazy eye) may be present.

An ophthalmologist tests the corneal light reflex through an exam called the Hirschberg test, in which a light is shined into the eyes and the location of its reflection is observed.

Eye misalignment is more often seen in children than adults. Due to this, the Hirschberg test is a routine part of childhood eye exams. It is also used to detect eye misalignment in adults.