There may be a slight discoloration that can be seen on the bottom left and right side of some LCD monitors. The slight shadow is caused by a lesser amount of light from the fluorescent lamps reaching these corners. These lamps produce less light at their extreme edges and the discoloration is inherent to the LCD technology used in the displays. This becomes more noticeable when larger LCD panels are used.If the patches are extremely evident or occur in other places on the LCD screen, they may be caused by physical damage. This can occur by dropping, rough handling, or placing heavy objects on the computer or screen. In these cases, service will be required.