I have Microsoft Outlook set to alert me every hour to take an eye break. During that break, I try to do the following:
1) Look at something far away (25 feet or more) for 1 breath.
2) Look at my fingertips up close (about 6 inches from my eyes) for 1 breath.
3) Repeat 15 times.
If I am in the midst of something and the above routine will take me too long, then I just look at something far away (again, 25 feet or more) for 5 to 15 breaths. I also happen to use this time as a sort of meditation to let go of stress, re-focus, etc. I feel like this works reasonably well, but more often than not I don’t take the time to complete the full exercise.