The virus is transmitted by airborne. The onset of the disease is acute. The lesion of the eyes, as a rule, is preceded and followed by lesions of the upper respiratory tract, an increase in body temperature, an increase in the preauricular lymph nodes (more often in children). There is lacrimation, photophobia, edema and redness of the eyelid skin, moderate blepharospasm, conjunctival hyperemia and low nonpurulent discharge (catarrhal form). Often, the disease is followed by the appearance of follicles (follicular form) or films. The filmy form is observed mainly in children. The damage of the cornea is rare, in the form of epithelial punctate keratitis, which soon dissolves without a trace. The diagnosis is made on the basis of a combination of conjunctivitis with catarrh of the upper respiratory tract and regional adenopathy, as well as data from cytological, serological and virological studies.