In our eyelid there is a thing called tarsal gland, which can secrete grease all the time. Though people close eyes for a long time during sleeping time, the grease is still in secretion, and mixed with the impurities from tears and dust that into the eyes during daytime, then eye boogers form. It is not a disease if the quality of eye boogers is small. But if the eye boogers increases suddenly, even make the eyelid and eyelash stick together and you hardly open eyes, you may suffer from some eye diseases, caused by bacteria infection, and then you should go to the hospital treatment.