Depending on your computer, you may be able to change the resolution of your display to make the desktop and images appear larger or smaller.
Open System Preferences and click Displays. If necessary, click the Display tab.
You can also calibrate your monitor to customize the way it shows images and change how many colors your monitor displays.
Note: The information is this document comes from Mac OS X Help, the help system included with your computer. It is based on Mac OS X 10.1.2. If a different version is installed on your computer, choose Mac Help from the Help menu. Updated and expanded information may also be available in other Knowledge Base documents.