This is very true. Flux helps with color, but it can still be a bright rectangle in a dark room and cause a lot of eye strain.
The best thing I can recommend is reducing your monitor's brightness to the same level as your periphery, including turning on a lamp to illuminate your surroundings (called bias lighting). Try something as simple as this: https://cdn.instructables.com/FUD/A1WU/GX3M1GEN/FUDA1WUGX3M1...
