Your eMachines desktop computer is very customisable, and includes an option to adjust the brightness of the monitor. If the computer screen is too dark for you to be able to see the displayed content clearly, make the screen brighter; if the screen is so bright that it is causing you to squint your eyes, turn the brightness down.
Click the brightness button. On most eMachines monitors, the button is below the screen and has an icon that looks like a sun.
Click the "+" and "-" buttons until the brightness is adjusted to your specifications.
Click the "Brightness" button to close the brightness option.