It seems that you have a feeling as if there is sand in your eyes right? So, to be honest, that is not sand in your eyes but some kind of eye disease you know. From what I can see, you are infected with trachoma which is a common eye disease and it could make you feel there is something stuck in your eyes. So, I recommend that you consult a doctor and take immediate actions as soon as possible.
There must be the sand coming into your eyes yesterday. During your sleep, this dirty things will not absorbed by the corneal. Or it is the excretion that is sediment after you have experienced in the bad environment. You should wash your eyes and see whether they are red. If they are not serious, you could use the eye drops to clean the eyes. Or else, you could go to the hospital to see the doctor.