75hz refresh rate on new monitor.

An LCD's 'refresh rate' is not like a CRT's refresh rate, in that it is not 'blinking' light on and off as a result of how often the screen image is redrawn. That being the case, the 'refresh rate' you see referred to is not governed as a rate the monitor illuminates, but how often the image is redrawn on the screen. The LCD has a backlight which is essentially constant. This is why LCDs are known for producing less eyestrain. This is also why you can't adjust the 'refresh rate' on most LCD monitors. Some LCD TVs offer a 'refresh rate' of 24hz, 120hz, and even 240hz to redraw the image faster for high speed image response for HD content or gaming, or slower for film style authenticity. This does not change illumination.