Vertical aperture height from the lower eyelid to the upper eyelid.
Abnormal lower eyelid positions shoul be noted
Normal: 8-12 mm
Marginal reflex distance
Distance from the cornea light reflex and upper eyelid margin.
A negative value is given if the upper lid margin obstructs the corneal reflex
The value is obtained measuring the palpebral shift until the reflex appears
Normal: 4-4.5 mm
Distance from upper palpebral margin position in down-gaze and the upper palpebral margin position in up-gaze.
Securing one's tumb over the brow the frontalis muscle contribute is negated.