The association between symptoms of asthma, rhinoconjunctivitis (RC) and allergic conjunctivitis (AC) is frequent, and AC is considered a comorbidity of asthma and allergic rhinitis (AR). Ocular symptoms are often underestimated and undertreated.Differences according to gender were reported, because girls present symptoms more frequently. The development of RC depends on genetic and environmental factors, and recent studies have indicated that gender, family history of atopy, early sensitization, food allergy, and atopic dermatitis are risk factors for allergic RC. There are six well-defined clinical forms of ocular allergy: seasonal AC, perennial AC, vernal keratoconjunctivitis, atopic keratocon-junctivitis, and contact blepharoconjunctivitis.