Ok, from what you said, I can see that you are quite worried about your eye health. Anyway, it is good for you. So, as you can see, long time of exposure to computer screen would let our eye take in a lot of radiation and harmful lights, leading to watery eyes, red eyes, dry eyes, and maybe other serious infections. So, you should try hard to protect your eyes, through taking breaks from time to time, more tea, more fruits and vegetables, and a lot of vitamin pills, proper amount of rest, and so forth. Also, sometimes eye drops also help with your concern. Hope you find my tips good.