Eyelids

Transverse section of the dorsal or ventral eyelid of a pigeon (HE): detail

The connective tissue of the eyelid is strengthened to a tarsal plate or tarsus (tarsus palpebralis) that is externally covered by skin (facies cutanea) and internally by conjunctiva (facies conjunctivalis). At the fornix conjunctivae, the palpebral conjunctiva (tunica conjunctiva palpebrarum) is continuous with the bulbar conjunctiva (tunica conjunctiva bulbi).

The muscles present are the striated muscles of the m. orbicularis oculi and m. levator palpebrae dorsalis (dorsal eyelid) or m. depressor palpebrae ventralis (ventral eyelid) and smooth muscle fibers of the m. tarsalis superior or inferior (m. orbicularis palpebralis, NAA).