My eyes are so very important and I spend a lot of time in front of monitors. Two useful pieces of software. An extension for Google Chrome called Dark Reader – https://darkreader.org/ which sets website backgrounds to black rather that the obligatory white. I use this all the time, it has a facility to be activated between certain times of day and also at sunset to sunrise once you’ve given it your map location (use Google maps to get latitude and longitude for your location) but I like it all day. Another feature is the ability to bypass various sites which don’t play nicely with a black background like WordPress or to whitelist only the sites that you want to use it with.
Another useful piece of software which I’ve recently started to use is IRIS, https://iristech.co/ this isn’t free, nor is it is expensive but it is great. It can reduce the colour temperature of a monitor/s (reducing blue light) and brightness between times or, as I have it setup, between Sunset and Sunrise once you have entered your location. There are many other useful features including setting up a list of applications such as suspending the software whilst running colour fidelity critical software like all my photo editing software programs once you’ve set it up. There’s even a AI feature to hook up a webcam which I’ve done (for security with sound disabled in Windows settings and pointing at a blank wall), to automatically sense room brightness and adjust monitor/s brightness accordingly. Together they really do help reduce eye strain.
I have no affiliation to either of these companies or their products.