To keep debris and objects from our eyes and to take them out after they’re in, our eyes utilize built-in biological mechanisms. Eyebrows direct particles-laden forehead sweat from into your cheeks. The blinking process re-moisturizes your eyeball, and tears flush objects onto the surface. Eyelashes help in sweeping objects off. Sometimes, a dust particle or a small piece of debris, such as an eyelash, could be able to get through your eyes and get into your eye. It could happen because of insufficient protection for your eyes, the use of makeup or eye drops that are contaminated, or just luck (or luck).