All monitors age. With time, the backlighting grows dimmer and often shifts toward yellow. The decision of when to retire a monitor is up to you. There are many variables, but you can expect to get 8,000 to 12,000 hours of color-critical work out of a monitor before you retire it to non-color-critical applications. You can extend the life of a monitor by turning it off when it is not in use, using a screen saver, and lowering the luminance set point.