Tear Film Break-Up and Gritty Eyes
As part of our eyes' normal function, tears are produced, spread over the eyeball, and continually washed out through tiny holes on the edges of the upper and lower eyelids.
Our impulse to blink is due to our tear film thinning out and evaporating, giving us the automatic reflex to blink and spread the tear film. The process of the tear film thinning out is called tear film break-up.
When not enough tears are being produced to keep the eye moist between blinks or our tears are out of balance, the tear film can break up too quickly–before our impulse to blink. This causes dry spots to appear on the eye's surface (cornea). These dry spots can make us feel like we have sandy or gritty eyes, or feel like something is in our eyes.
Even if all the components of our tears are normal, dry spots can still appear in certain situations. The corneal cells on the eye's surface have very delicate structures that allow the tears to "stick" to the eye. If these structures are damaged, tear film can break up too quickly.
You may not know that you have damaged corneal cells, but your eyes may feel dry and have a burning sensation often described as gritty eyes. Your eye doctor will be able to see surface damage during an eye exam using a diagnostic fluorescent stain and a special instrument called a slit lamp. The corneal cells can heal quickly if they are coated with a lubricant that protects them and allows moisture to stay on the eye's surface longer.
Using a drop such as SYSTANE®, which has a unique lubricating system, will help keep moisture on the eye longer to help relieve the uncomfortable feeling of gritty eyes.
