When the sand is in your eyes, your eyes will feel painful and get watery with no control. Your foreign feeling of the eyes may be caused by the eyes infection. Your eyes may get invisible bacterium which activates in your eyes. You need to use some eye drops with anti-inflammation to make your eyes get moisture and comfortable. You could also use the warm compress to make your eyes get comfortable.
According to your description, it is possible that your eyes get conjunctivitis, which is the inflammatory reaction of the conjunctiva to the outside or the organism itself, or your eyes get tracoma, which presents itself as itchy eyes and sand-like particles on the surface of the palpebral conjunctiva. There are several reasons to cause conjunctivitis, therefore you had better go to the doctor's to have an eye examination to find out the exact cause, so that you can tke correspondent treatment. If your conjunctivitis is caused by bacteria, then you can use antibiotic eye drops such as tobramycin to apply into your eyes two or three times a day. If your conjunctivitis is caused by viruses, then you can use antiviral eye drops. As to tracoma, it is a kind of chronic communicable eye disease caused by chlamydia trachomatis, and it is likely that you get infected by other people who get tracoma. You should also go to the doctor's for medical treatment.
The first thing you should do is to check whether there is foreign object in your eye. If so, you can get the object out by rinsing your eyes with water or flushing it out with artificial tears. After doing this, your eyes will feel better. If there is no foreign object in your eyes, you may experience an allergic reaction. When you are exposed to allergen which may be the food you eat, something in your house or pollen, your eyes will have foreign feeling. In this case, you should remove the allergen immediately and then apply over-the-counter eye drops or drugs prescript by your doctor. The uncomfortable sensation can be the result of eye irritation. If you are female, the cosmetics you use may irritate your eyes. Windy, smoky or dry environment can also irritate your eyes. Antibiotic eye drops and artificial tears that can moisten your eyes may be helpful.