A case report of a 22-year-old patient with accommodative paralysis is presented including (1) the five-year history beginning with infectious mononucleosis; (2) recent clinical examination showing accommodative paralysis and reduced pupillary responses to light and near; (3) objective recordings confirming both the absence of any accommodation and the presence of pupillary responses to monocular and binocular near stimuli and to light, the latter with pupillary escape; and finally (4) neuropharmacological tests showing 7-diopter accommodative responses to pilocarpine (an acetylcholine substitute acting directly on the ciliary muscle receptor sites) and absent responses to demecarium bromide (a cholinesterase blocking agent which potentiates neurally released acetylcholine). Infectious mononucleosis includes ocular signs and symptoms. In young persons with accommodative difficulties, infectious mononucleosis should be suspected.