July is Dry Eye Awareness Month.

To help draw attention to this growing medical problem, the Tear Film and Ocular Surface Society (TFOS) reports it is releasing a new study based on the research of 150 clinical and basic research experts from around the world.

Here are 10 facts about dry eye you need to know:

1. Dry eye disease is a global problem. It afficts more than 30 million people in the United States alone, and is one of the most frequent causes of patient visits to eye care practitioners (Source: TFOS).
2. There are three kinds of tears. There are basal tears, reflex tears, and emotional tears. Basal tears are necessary to your eye health and vision. They are in your eyes at all times to lubricate, nourish, and protect the eyes. Reflex tears are those that form to protect your eyes from irritants. They wash away debris when it enters the eyes and help fight bacteria to prevent infection. They can also be triggered by the wind or onions. Emotional tears occur when you’re emotionally sad or very happy.