Video: What is dry eye? by CAO and Dr. Shawn Poitras Article Credit: Canadian Association of Optometrists ( opto.ca ) What is dry eye? The surface of the eye is coated with a layer of tears. Dry eye occurs when the eyes don’t produce enough tears or produce tears without the proper chemical composition. 1   What causes dry eye? Many factors can contribute to dry eye, including aging, hormonal changes, UV exposure, environmental conditions (e.g., exposure to air pollution, win