Olopat Eye Drops 0.1% 5ml 1packHow Olopat Eye Drops 0. 1% with Olopatadine HCl Relieve Eye Allergy Symptoms Olopat Eye Drops 0. 1% contain Olopatadine HCl, an antihistamine that helps reduce itchiness, redness, and swelling in the eyes caused by allergies. These eye drops provide fast relief from common eye allergy symptoms like those caused by pollen, dust, or pet dander. Key Benefits of Using Olopat Eye Drops 0. 1% 0. 1% Olopatadine HCl for effective allergy relief in the eyes.