AGI Thanks for this tip as well. Are you sure though, that quality updates do not affect image rendering? KB5015684 changes my Windows 10 version to 22H2 making the system unusable. This update seems to belong to the category of Quality Updates.
No, of course not, there is no way for me to know what Microsoft considers a quality upgrade for LTSC versions in the future and how/if different OS changes will affect people's eyestrain.
However, in my understanding the whole point of an LTSC is that your Windows version number stays the same, so if you are on Windows 10 21H1 LTSC, you should not get any updates that will change your Windows version to 22H2.
In general, I am just pointing out possible options - if they might be viable in your situation is something only you can decide. I feel possible software alternatives are the easiest options to try though. It's probably a lot more feasible for many users to download an LTSC Windows version, install it on an old hard drive and see if it helps with the eyestrain, as opposed to a larger investment like ordering new hardware such as a Sun Vision display.