The same applies to our eyes. Rubbing the eyes disturbs the delicate three-layered stucture of the tearfilm and causes it to break up forming dry spots. The first aim should be to avoid as many as possible of the causes mentioned above. Or, worse, a heater or air-conditioner. Make sure ventilation in the car is not directed at your face.
Many students use too bright study lamps positioned too close to the face.
The problem is caused by staring in one direction for long periods. This reduces the blinking frequency and increases evaporation time. Develop the habit of frequently looking away. Every time you change your direction of gaze, you blink your eyes. Changing treatment for glaucoma, hipertension, hormone replacement, contraception, allergies, etc.