A compatible video card. Your computer's video card drives the monitor. It determines the resolution and color depth of the image on the screen. The capabilities of your video card should match your monitor.

System software. Your computer system must be configured correctly for the type of monitor and video card you're using in order to display information accurately on the screen. Your operating system must have the right kind of software driver to mediate resolution and color information between the monitor and the computer system. When you use a multiscan monitor, the operating system is what allows you to switch between resolutions.

Power and data cables. These cables are usually supplied with the monitor. The power cable runs from its own power source to the monitor; the data cable connects the monitor to the monitor port at the back of the computer.

A static-free cleaner. No matter how high the resolution of your monitor, your images will still be blurry if they're covered in a layer of dust. All CRT screens produce a static charge that attracts more dust than surrounding surfaces do. Check your monitor's manual for the best cleaning methods, or purchase static-free alcohol wipes to clean that dirty screen.

A glare fighter. Glare is one of the main contributors to eyestrain and headaches. If you can see reflections from lights and windows on your monitor, you may need an anti-glare device. A hood that extends over the top of the monitor can brighten an image washed out by harsh overhead lights. An anti-glare screen that fits over the front of the monitor can reduce reflections from windows and room lamps.