The refresh rate is the Hertz frequency at which the screen is redrawn. A flickering monitor can contribute to eyestrain and headaches. Increasing the screen refresh rate to at least 75 hertz for CRT monitors
and 60 hertz for LCD monitors
while using the native resolution will generally produce less flicker and strain on your eyes. The available rate and resolution
options are based on the video adapter and it's driver, and of course your monitor and it's drivers (if available).