Changing How the Keyboard Works on Your Mac
You can access the Keyboard pane through the Universal Access dialog on your Mac. The Keyboard pane offers several settings that can make using a keyboard easier, especially if you need special accommodations.
If you have difficulty doing complex key presses, like the Command+Option+= combination for Zoom, try turning on Sticky Keys. The Sticky Keys option, which is controlled from this pane, lets you press the keys one at a time to effect the desired combination. For example, you would first press Command, then Option, and then the equal sign (=). You can also control what feedback OS X gives you when you do this.
Another problem some people have is unsteady hands; they may accidentally press a desired key more than once. Another option on this pane lets you set a time delay between key presses to reduce this problem.
You can find additional settings related to the keyboard in the Keyboard & Mouse window of System Preferences.
A number of specialized keyboards are available to assist with various problems, ranging from repetitive stress injuries to users who can use only one hand. As long as a specialized keyboard uses a USB interface, the keyboard should work on a Mac.