Helpful contrast makes text on the screen easier to read. Great feature for those with visual impairments.
2. Mouse Keys
This allows you to use the arrows on the numpad to move the mouse around the screen. Very helpful for someone with poor motor control. The mouse moves slowly, if you want it to.
3. Magnifier
Wherever you move your mouse, the computer magnifies that area for you and puts it at the top of your screen. Very helpful for those with a visual impairment which prevents them from seeing clearly such small text on the screen.