A desk positioned so that you can view things beyond it at a distance has been the best remedy for my eyestrain, and I say that as someone using cheap oversized 1080p screens. An expensive high DPI monitor might be more convenient than rearranging a whole room to reorient an office desk, but in my experience, the value it provides is fantastic. No matter the quality of the monitor, if my ability to adjust my focus is impeded by a room's layout, then my eyes will feel the same strain they'd have if I'd been staring at a wall all day at an arm's length distance.
Interestingly, the photo search results I get for "desk ceo" all show the desk oriented in the ideal way (i.e., not facing a wall): https://kagi.com/images?q=desk+ceo
When the sun is not line-of-sight, and you don't have any bright flares off other objects (like car windows or chrome).
That gives you natural light, it should be even left/right, and it happens to be awesome fill light for looking good on videoconf.
You can also glance around your monitor to refocus at a distance, frequently.