Functions of the internal muscles inside the eye, eyelid, external muscles of the eye, including voluntary and tracking movements and fixation of the eye, lacrimal glands, accommodation, pupillary reflex, impairment such nystagmus, xerophthalmia and ptosis. 

Nystagmus and ptosis are frequent symptoms of a rare condition. 

The function of the tear glands and ducts (b 2153) may be disturbed in Treacher Collins Syndrome