The refresh rate is the amount of times a display's image is repainted or refreshed per second. The refresh rate is expressed in hertz
so a refresh rate of 75 means the image is refreshed 75 times in a second. The refresh rate for each display depends on the video card used. You can change the refresh rate in the display properties. However, if you change the refresh rate to a setting that the display or video card cannot support, the display goes blank or the image becomes distorted. It is recommended to consult the display and video card manuals before changing the settings to determine the supported refresh rates. An older refresh rate standard, developed by the Video Electronics Standards Association (VESA Local Bus
), was only 60 Hz. This refresh rate caused the display's image to flicker causing eye fatigue and headaches in users. A new standard set the refresh rate to 75 Hz. It is believed that 70 Hz or higher eliminates the flicker. When purchasing a monitor, look for a refresh rate of 75 to 85 Hz.