The long screen time is the main cause. The perfect glasses, light, or monitors might make you feel better in the short term, but the same environment and low activity might still lead to eye strain. I have been struggling with eye strain for a long time. The best practice I’ve found is to leave the desk and go out for a walk. I have even built an app[1] to help with that.
[1]: https://blog.damnever.com/en/2024/reminding-myself-to-take-a...