Orbital septum

The orbital septum (palpebral ligament) is a membranous sheet that acts as the anterior boundary of the orbit. It extends from the orbital rims to the eyelids.

In the upper eyelid it blends with the tendon of the Levator palpebræ superioris, and in the lower eyelid with the tarsal plate.

Medially it is thin, and, becoming separated from the medial palpebral ligament, attaches to the lacrimal bone at its  posterior crest.

The septum is perforated by the vessels and nerves which pass from the orbital cavity to the face and scalp.

With age the septum may weaken, and as a result orbital fat may herniate forwards. The operation to correct this is called blepharoplasty.