[spython]

I feel like one cause of eye strain might be psychological: I find my eyes mostly strained when I'm overly fixating on something, when the project 'must' be completed, when the bug 'must' be found. My eyes in those moments feel like the fingers of an overly anxious climber who uses way too much power in his grip, and as a consequence tires way too fast.

As the strain comes from tension, the way out of the strain is to let go of the tension, and try not to grip with the eyes but to observe calmly, just as you would calmly observe the water flowing in a river.

Observe how tense the muscles around your eyes, around your forehead are. Observe whether your jaw is tense. See if you can allow your facial muscles to relax while working, and if you can allow your gaze to remain soft. Make pauses to relax the grip (the metaphorical grip on the situation you are in, as well as the actual muscle tension) every time you catch yourself tensing up.

[youniverse]

This is great advice.