- Palpebral fissure length: The horizontal distance between the inner and outer canthi (corners) of the eye. - Marginal reflex distance-1 (MRD1): The distance from the corneal light reflex to the upper eyelid margin. - Marginal reflex distance-2 (MRD2): The distance from the corneal light reflex to the lower eyelid margin. - Intercanthal distance: The distance between the inner canthi of both eyes. - Vertical palpebral fissure height: The distance between the upper and lower eyelid margins at the mid-pupil line.
