The present study will be carried out to evaluate the antiallergic efficacy of Bepotastine besilate 1.5% free of preservatives versus standard treatment with 0.2% Olopatadine hydrochloride with 0.1% benzalkonium chloride as preservative in adult patients diagnosed with allergic conjunctivitis.

The antiallergic efficacy will be evaluated by the reduction of ocular signs and symptoms and by the resolution of non-ocular symptoms (rhinorrhea, congestion, and nasal pruritus), as well as the effect of the preservative and its relationship with the cytotoxicity of the ocular surface. Also will evaluate the safety of both products.

Inclusion Criteria:

• Patients older than 18 years old.
• Clinical diagnosis of allergic conjunctivitis and active allergy with at least 2 points on itching and hyperemia scale.
• Patients with history of allergic conjunctivitis.
• Patients who accept no to wear contact lens during the duration of the trial.
• Patients who accept no to use any other medication by any delivery route.
• Patients with intraocular pressure controlled (less than 18 mmhg)

Exclusion Criteria:

• Patients who have undergone refractive surgery within the 6 months prior to the start of the study
• Patient with ocular or systemic active diseases
• Patients who are participating in another trial
• Patients who have used eye medication in the last 15 days and/or who have received anti-inflammatory drugs (corticosteroids and/or NSAIDs) and/or antihistamines by mouth or intravenous.
• Patients hypersensitive to any component of the products: Bepotastine besilate, sodium chloride, monosodium phosphate dihydrate, sodium hydroxide, Olopatadine hydrochloride, benzalkonium chloride, dibasic sodium phosphate, hydrochloric acid, edetate disodium or povidone K29 / 32.
• Women who are breastfeeding and pregnant.