I started using reading glasses (non prescription) a while ago when I was getting a lot of migraines. My vision was fine but I had difficulty switching focal lengths. The glasses just made it a little easier and my eyes felt a lot better at the end of the day. Migraines reduced too.

The other simple one is to just increase font size when you’re feeling strain. I’ll often change my font size when I’m in poorly lit conditions or if it’s the end of a long day.