Approximately 10% of the population is left handed and this large minority is often overlooked in designing user interfaces. Mice are particularly problematic.
- Standard pointer sets are right-handed in that arrows point north-northwest like the index finger of the righthand while holding mouse. A left-handed mouse is better represented by an arrow pointing north-northeast. (Logitech [L1 ] provides left-handed pointers with their mouse drivers.)
- Documentation (especially 'Windows documentation) often refers to the "left" and "right" mouse buttons when these are exactly opposite for a left-handed mouse. (UNIX documentation often uses MB1 (the mouse button closest to the keyboard) through MB3 (the mouse button farthest from the keyboard).)
- Some tools like Autohotkey presume that the user can click a left modifier key while using a mouse. This isn't true for left-handed mice.
(By "left-handed mouse", I mean a mouse on the left of the keyboard with the mouse buttons "reversed" from their right-handed factory defaults. Some left-handed users suffer with right-handed mice (on the right of the keyboard) and others only move their mouse to the left of the keyboard but don't bother swapping buttons.)