Schematic representation of papillary and follicular conjunctivitis. A, In papillary conjunctivitis, the conjunctival epithelium (checkered blue) covers fibrovascular cores with blood vessels (red), and the stroma contains eosinophils (pink circles), lymphocytes, and plasma cells (blue circles). B, In follicular conjunctivitis, the conjunctival epithelium covers lymphoid follicles, which have a paler germinal center surrounded by a darker corona (central pale blue surrounded by purple), and the surrounding stroma contains lymphocytes and plasma cells (small blue circles).