part_of part of part of superficial_to camera-type eye organ subunit ectoderm-derived structure ocular surface region eye surface The integrated unit (of the eye) that consists of the conjunctiva, the corneal surface, and the ocular mucosal adnexa including the lid margins and the meibomian gland openings, the lacrimal glands and the lacrimal drainage system, all which are critical to maintain ocular surface integrity and provide protection from external antigens and pathogenic microorganisms. ocular surface eye surface region surface of eyeball