Well I finally gave in and installed the colour profile for BenQ EW2440L I downloaded from BenQ website. Could not notice any difference with any image on http://www.lagom.nl/lcd-test/ although I don't have a trained eye. Made sure "Use my settings for this device" was checked under Color Management and the profile I downloaded was the only one listed there. Tried restarting at that point and noticed no difference. Tried looking at an image and checking and unchecking "Use my settings for this device", which should switch between the profile I downloaded and my system default (sRBG IEC61966-2.1 apparently), and still could not notice anything. Did not alleviate eyestrain either.
Also looked at some guides about installing ICC profiles and went into "Change system defaults" and checked and unchecked "Use Windows display calibration" and also noticed no change.
I hope I didnt screw up the default Windows profile with all the fiddling.. hitting reload current calibrations and stuff like that trying to get it to work.
Going to try turning the backlight off on my keyboard never thought of it before as it is so dim but I'm sure it could add up.
Still seems like I should notice something though and I'm missing something. Looked at color profiles folder in system32/spool/drivers/color the default icc profile is only 4 KB and the one BenQ provided is 101 KB. Gotta be something in all that extra information?