Histology Of Conjunctiva

The conjunctiva is a tissue that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of unkeratinized, stratified squamous epithelium with goblet cells, and stratified columnar epithelium. The conjunctiva is highly vascularised, with many microvessels easily accessible for imaging studiesBlood supply
Blood to the bulbar conjunctiva is primarily derived from the ophthalmic artery. The blood supply to the palpebral conjunctiva (the eyelid) is derived from the external carotid artery. However, the circulations of the bulbar conjunctiva and palpebral conjunctiva are linked, so both bulbar conjunctival and palpebral conjunctival vessels are supplied by both the ophthalmic artery and the external carotid artery, to varying extentsMicroanatomy
The conjunctiva consists of unkeratinized, both stratified squamous and stratified columnar epithelium, with interspersed goblet cells.The epithelial layer contains blood vessels, fibrous tissue, and lymphatic channels.Accessory lacrimal glands in the conjunctiva constantly produce the aqueous portion of tears.Additional cells present in the conjunctival epithelium include melanocytes, T and B cell lymphocytes.

Function
The conjunctiva helps lubricate the eye by producing mucus and tears, although a smaller volume of tears than the lacrimal gland. It also contributes to immune surveillance and helps to prevent the entrance of microbes into the eye.