The monitor,screen,adapter or display of a computer is the primary user interface. Monitor problems are some of the most common computer problems since the voltages inside a monitor can be as high as 10 KV. Many of the problems can be fixed yourself by simply changing the settings but in a few cases you may have to either replace or repair the monitor.
The monitor/display flickers - Check the refresh rate. If the refresh rate is 50 Hz/ 60Hz (depending on which country you stay), it can be affected by interference from electrical power signals like those from fluorescent lamps . Increasing the refresh rate to 72Hz is recommended , since higher refresh rates reduce eyestrain and headaches.
The display on the monitor is not steady - This is a result of power system interference from users of the power grid, particularly UPS, power tools and heavy machinery. Try changing the position of the monitor.
Dark Spots on the Screen. - Move speakers,USB modem and other magnetic devices away from the monitor.
Set your monitor/display pixels to the software requirements. some softwares require higher pixels to run or to be displayed. some media players, web applications, video games applications and photo editors/view softwares have option to view photos on low or high quality