Pointers are mice, trackerballs and joysticks.
There are many different versions of each available. An individual who is unable to use an 'off the shelf' mouse may be able to use an adaptation, for example a one click mouse or miniature mouse. There are variations is the positions of mouse buttons. Trackerballs are available with different sizes of ball, in different locations. Thus an assessment is valuable to explore the full range available.
For people who can control the position of the pointer but cannot press the selection switch, an additional 'select' switch can be added. Alternatively, with a dwell facility, the program will automatically accept an item without the need to press a switch, once the pointer has been held over that symbol/word/letter for a given, but changeable, time. Not all programs offer this dwell facility but it can be added using an add-on program.
Using a pointer can also be made easier by modifying the cursor. The colour, size and shape of the cursor can be modified, as well as the colour of the background. The speed of movement of the cursor and its acceleration can be changed on most computers via the control panel.