There may be the sands of other dirty things coming into your eyes. Then they are not absorbed fully by the eye cornea at night. Thus, your eyes may easily get the gunny situation in the morning. You could use the eye drops to release the symptom. Or else, you could go to the hospital to have a full check on the eyes.
You must got some eye discharges in night that can cause the eyes gunny. Just look at a mirror is there something around your eyes corner. If it is, it is just eye discharges. Just use clean water and clean it. It is a normal for eyes pass some discharges. And it usually harmless. But if you also feel eye pain and your eyes appear red, you'd better see a doctor.
Well, from your description, I think you may have got dry eyes. As we know that if you do not have the necessary balance of these three layers in your eyes, or if your eyes do not make enough tears to coat the eye, you may have a condition, which is known as dry eye. So for your situation, you can just take something for inflammation, like Omega-3 fish oils, and use eye drops for a long time. I think it can be effective after a long time. For sake of safety, you should use the safe brand, and just make sure you get the kind with no preservatives for they can make the problem worse in the long run. Besides, if your situation is serious, you might also check with your eye doctor, so that you can make sure it is fine.
We have a gland named tarsus in our eyelids, their opening exist in the edge of eyelids. The oil that secreted by tarsus is the gum, it would moisten the eyelids and cornea, prevent the tears go out of eyes to erode the skin around eyes. It also would prevent dry eyes from tears evaporation. These oil and the dust and tears in the eyes mixed together to form the gum. If some one's eyes are inflammated by the virus, the gland of tarsus has been stimulated by the disease, the oil secrete more than normal, the white blood cell which used to kill the virus will mixed into the gums, it will be more than normal. So, for the above reason, if some one has the eyes disease of trachoma, conjunctivitis or other eyes inflammation, the gum will be increased. It would be a signal of eyes inflammation, you must to to hospital on time!