These are slight arches of bone just above the supra-orbital margin. They are most prominent medially tapering into the squama laterally. They are more prominent in males.

Cilia is the Latin term for an eyelash or hair-like structure and stems from the Greek killo for trembling or winking. It was applied to the eyelashes because of their trembling or winking motion.

Arcus superciliaris

Arcade sourcilière