A dirty monitor is not only a distraction, but it can damage the monitor as well. Dust is everywhere, making it difficult to avoid–but it can be controlled. Cleaning the monitor should be done weekly, depending on the climate you live in and how much dust is in your home or office. Cleaning an iMac monitor is easy, and well worth the small amount of time it takes.
Turn off the monitor and unplug it from whatever power source it's plugged into.
Wipe away as much dust as possible with a soft, clean, lint-free cloth.
Mix equal parts 3% hydrogen peroxide and distilled water in a spray bottle.
Spray the solution onto a clean soft lint-free cloth and gently wipe the monitor with it. Do not press too hard on the screen, as that may damage it.
Wipe the monitor dry with a soft, clean lint-free cloth, and do not plug it back in until all moisture is removed.