Among the different forms of allergic conjunctivitis, atopic keratoconjunctivitis has distinct characteristics, defined by a more common onset in late adolescence or early adulthood, but also affecting the elderly, and with a higher prevalence in male individuals. However, the prevalence of atopic keratoconjunctivitis is scarcely investigated, and the data are often uncertain because other allergic nasal or respiratory disorders occur concomitantly. Mast cells, eosinophils, basophils, and T cells are involved in the pathogenesis of atopic keratoconjunctivitis. Despite its denomination as atopic, negative responses to skin tests or in-vitro immunoglobulin E tests are common. In fact, atopic keratoconjunctivitis can be attributed to a combination of T-helper-1 and T-helper-2 responses, but a higher prominence for T-helper-1 cells was found. The most common symptoms of atopic keratoconjunctivitis are bilateral ocular itching, burning, and tearing with a perennial presentation, although some patients may have seasonal exacerbations in winter or summer. Other symptoms such as photophobia, blurred vision, and mucous chewy discharge, owing to the accumulation of cells and mucin, may occur. The diagnosis of atopic keratoconjunctivitis is mainly clinical, as accepted diagnostic criteria or laboratory tests are not available. The treatment of atopic keratoconjunctivitis is aimed at controlling symptoms, decreasing relapse and exacerbations, and reducing vision loss. Therapeutic options comprise topical ophthalmic drops, including cromones, antihistamines, corticosteroids, and calcineurin inhibitors. Topical ointments are also available for corticosteroids and calcineurin inhibitors. Severe forms may require systemic medications including antihistamines, corticosteroids, and calcineurin inhibitors. Atopic keratoconjunctivitis therapy in the elderly does not differ from the adult population, but the occurrence of multi-morbidities and concomitant drug treatment, which are common in this age group, requires a careful evaluation to determine appropriate and personalized treatment.