The 20/20/20 rule goes like this: Every 20 minutes, look at something 20 feet away for 20 seconds.
Twenty seconds gives your eyes time to relax, and the 20-foot condition requires you to focus far away.
Also, you can just tell people what you’re doing. Use that little chat feature to say at the beginning of the meeting, “My eyes are going buggy from all the screen time, so if I look away sometimes, it’s only to give them a rest. I’m still listening!”
Your computer probably has a night light setting that reduces the amount of blue light coming from your screen. You can set it to turn on automatically at sundown and off again at sunup.
Learn more about eye strain in Zoom meetings here.