A lot of things can be wrong if you setup a new monitor or never bothered to calibrate an old one. The screen could be to bright or dark for instance. I always hated calibrating monitors because it meant that I had to press all those tiny buttons on the monitor to access the functions but it is necessary for the best viewing experience.
Screen Check, discovered by Uneasy Silence, is a page that helps check two different parameters: Brightness and Color. It’s by no means a full calibration software but it aids with those two parameters. Both are shown as bars on the same screen. The first displays a range from white on the left to black on the right, all should be visible on screen. If they are not you need to adjust the brightness and contrast setting.
The suggested settings at the website are not optimal for all monitors. The settings for my Samsung Syncmaster 19″ flat screen monitor for instance are perfect at +45% Brightness and +38% Contrast. If I set the contrast to a higher value the darker parts of the bar become black as well.

The second bar displays red, green and blue colors which should be fluent from left to right. If they are not you might need to adjust the color setting of your display adapter to display a higher color quality.

Monitor Calibration Wizard
Calibrate Your Flat Screen Computer Monitor
Upgrading to a bigger computer monitor
Online Computer Monitor Calibration
Computer Monitor Calibration
Samsung Syncmaster 2263DX
[...] 原文链接。 [...]
[...] software programs available (read: Online Computer Monitor Calibration, Monitor Calibration Wizard, Easy Monitor Calibration or Calibrate Your Flat Screen Computer Monitor for additional options). The Eizo Monitortest tool [...]