The most important thing is blue light protection. You can buy blue light filtering glasses, or have a blue light filtering layer added if you already wear glasses.
Another thing you can do is take a small break every hour or two when you are not looking at screens. It's also good for your eyes to focus on objects far away instead of always looking at objects near you, so if you can stare out a window for a few minutes every once in a while, that can be beneficial. There are also methods with which you can "exercise" you eyes.