Boric acid is often an ingredient in eyewash products. It's predominantly used as a mild antiseptic and to maintain the pH of the eyewash solution. Boric acid eye washes can be used to clean and ease mild cases of irritated eyes. Bend your head forward and bring the cup to your eye. Press it tightly to your face around the eye. Then tilt your head back and open your eye wide. Move the eye around in all directions to allow the boric acid to cleanse the eyeball thoroughly.