Nowadays, the latest technology might be a main cause for the dry/bloodshot eyes. The people are working at the front of the computer and staring at the screens for a long period of time. The blink of the eyes is decreased. It will cause your eyes dried and strain. Generally, a person always blink his eyes 10 to 15 times per minute. However, when staring at the screen, the just blink only 3-5 times per minutes. So some ophthalmology suggested the 20-20-20 rule, suggesting that every 20 minutes, shift your eyes to look at an object at least 20 feet away, for at least 20 seconds to prevent eye strain.