<p>Dry eye patients often have very irritated eyes. Irritation causes the eyes to itch. Itching can also occur with <a href="https://www.verywell.com/eye-allergies-p2-3422071" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">allergies</a>, which is usually treated with anti-histamines. A well-known side effect of anti-histamines is dry eyes.</p><p>Burning occurs because one of the functions of the <a href="https://www.verywell.com/what-are-tears-made-of-3421862" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">tear film</a> is to lubricate the eye. When the tear film breaks down, the surface of the cornea dries out. The cornea, which is filled with nerves, fires an impulse to the brain to be interpreted as a burning sensation.</p>One of the hallmark symptoms of dry eye syndrome is the feeling of a piece of sand or other foreign body stuck in the eye. A foreign body sensation is produced when the eye is not properly lubricated. When this occurs, the brain sends a message back to the eye telling it to water excessively to flush out the foreign body.Redness is a sign of inflammation. When the eye is not lubricated properly, it becomes inflamed. Underlying inflammation is sometimes the root cause of a dry eye. Our tears are also responsible for maintaining ocular health by supplying nutrients to the tissues. When the nutrient pathway is interrupted, our eyes become red and angry.<p>The tears supply a smooth optical surface for light rays to properly refract to the back of the eye. As the eye dries, the surface of the eye becomes irregular, causing blurred vision. Blinking renews the tear film, producing a smooth optical surface for a quality picture to be imaged on the <a href="https://www.verywell.com/retina-anatomy-3421686" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">retina</a>.</p>Most people are confused when the diagnosis is dry eyes, yet their eyes are tearing excessively. The tear renewal system simply overcompensates because the eye dries out. Reflex tears are produced instead of our regular every day lubricating tears. Tearing is also a natural way to flush out debris, as the eye and brain may think that a foreign body is trapped in the eye.The rate at which our eyes blink tends to decrease when we are concentrating on a task. Because blinking renews the tear film, a dry eye patient may actually blink at a much higher rate to ensure proper lubrication of the eye.