An aqueous ophthalmic solution containing relatively high concentration of olopatadine in solubilized form and process for making such solution is provided. The process for preparing the aqueous ophthalmic solution comprises a step of sizing olopatadine particles, preferably by using a microfluidizer, a ball mill or a colloidal mill. The solution is useful for providing enhanced relief from symptoms of ocular allergic disorders (e.g. conjunctivitis).