Vernal conjunctivitis was first described in 1846 by Arlt, who called it a variety of eczematous conjunctivitis. Vernal conjunctivitis is a chronic disease, of many years' duration. During the winter little disturbance is experienced, while with the beginning of the spring heat the eyes become reddened and photophobia and, above all, a great deal of itching of the eyes occur. The objective changes are presented in the tarsal conjunctiva and in the sclerocorneal limbus and its vicinity, while the rest of the bulbar conjunctiva and the fornix are normal.
In cases of the mild form the tarsal conjunctiva shows a white velum, or there is permanent hyperemia of the scleral conjunctiva, with ciliary injection; with the more acute form the tarsal conjunctiva is hypertrophied, with the formation of enlarged and flattened papillae, so that the surface has a cobblestone appearance. The changes in the limbus consist of pale, grayish red,