Eyelid Terminology and Measurements

Palpebral Fissure

• The palpebral fissure refers to the normal exposed area between upper and lower eyelids.

• It is measured between the margin of the lower eyelid to the margin of the upper eyelid.

• The normal palpebral fissure height (sometimes abbreviated PFH) is 8-11 mm. This is a key measurement that you need when assessing for ptosis (droopy eyelid).