Glands of conjunctiva

The conjunctiva contains two types of glands
(Fig. 1):


1. Mucin secretory glands. These are goblet cells
(the unicellular glands located within the epithelium),
crypts of
Henle (present in the tarsal conjunctiva)
and glands of Manz (found in limbal conjunctiva).
These glands secrete mucus which is  
essential for wetting the
  cornea and conjunctiva.
2. Accessory lacrimal glands. These are:

•  Glands of Krause (present in subconjunctival connective tissue of fornix, about 42 in upper fornix and 8 in lower fornix) and
•  Glands of Wolfring (present along the upper border of superior tarsus and along the lower border of inferior tarsus).

Plica semilunaris
It is a pinkish crescentric fold of conjunctiva, present
in the medial canthus. Its lateral free border is
concave. It is a vestigeal structure in human beings
and represents the nictitating membrane (or third
eyelid) of lower animals.


Caruncle
The caruncle is a small, ovoid, pinkish mass, situated
in the inner canthus, just medial to the plica
semilunaris. In reality, it is a piece of modified skin
and so is covered with stratified squamous epithelium
and contains sweat glands, sebaceous glands and
hair follicles.