why do our eyes feel like they have sand or grit in them when we’re very tired ?


why do our eyes feel like they have sand or grit in them when we’re very tired ?

In: 4050

Tears produced by our tear ducts help lubricate and hydrate our eyes. However, the longer we are awake, the tear quality declines. That makes our eyes feel drier and “crunchier” when we blink, similar to if they had grit or sand in them.

Sleeping a full night gives time for the tear ducts to reset to producing high quality tears again.

There’s the obvious which is that tear production tends to slow the longer we’re awake, but there’s another factor that was indicated in a pretty [interesting study out of Columbia University:](https://www.cuimc.columbia.edu/news/new-research-suggests-rem-about-eyes-not-dreams)

There’s also another function of REM, which is to allow the removal of dead cells and debris on the eyeballs in a gently and controlled manner. If you ever wondered what “morning eye gunk” was, in part it’s that.

This leads to a way to help reduce this feeling, at least for short bursts. You close your eyes and have your eyeballs do figure-8’s for a couple of minutes. It’s very refreshing, gives your vision a break, helps to boost circulation and remove some debris, while giving your tears time to build up.

Irritated corneal nerves. They are ‘naked’ and their concentration is so dense in the cornea.


Dryness is typically the main culprit. There are three main components to our tear film: oily layer, watery layer and the mucus layer. If there is any interruption in those layers, dryness can occur.

For example, if you don’t blink (close) your eyes completely, the meibomian glands aren’t activated and the oily portion of the rear film is at a deficit. Less oil makes our tears evaporate quicker thus making the eye dry.

If your vision tends to fluctuate throughout the day it’s possible they are dry. Using non-preservative artificial tears or lubricating eye drops will improve the corneal surface.