Does it feel unprofessional to use an eye saver app (to remind you to rest your eyes) or browser extension at work? It recommends to close your eyes for a while and watch further for relieving strained eyes and excessive staring at the monitor every hour or you can set your own time.
In my case many of my colleagues rarely take such explicit breaks and seeing me using the extension make some of them asking me whether I need to visit a doctor and different inappropriate comments. Some people understand it like a slacking as well.
I visit regularly a doctor and I'm fine, but I feel better with this reminder.
Edit: It's a small pop-up on the desktop. I'm not a robot and don't follow it every time but it appear when someone is staring at my monitor.