Why I feel like there is sand in my eyes

 
You could have a foreign body on your cornea or conjunctiva. It might be dust, a small insect etc. If so, it will need to be removed. There are other reasons why you may have that symptom. The outer surface of the eye is protected by a thin film of tears. This film is refreshed each time you blink. If for any reason, the tear film is broken, the surface of the cornea can dry up and feel rough. This can happen if there is reduced production of tears. It can also happen if you do not blink your eyes often enough. The commonest cause of this is staring at a computer or phone screen for too long. You must consult your doctor to find out exactly why you have that problem. You can then be treated appropriately.