crypt of Henle

Crypts of Henle are microscopic pockets found in scattered sections of the conjunctiva around the eyeball. They are responsible for secreting mucin, a proteinous substance that makes up the inner layer of tears. It coats the cornea to provide a hydrophilic layer that allows for even distribution of the tear film. The layer of mucin allows tears to glide evenly across the eye's surface[WP].