A left handed keyboard generally allows left handed users to follow their natural strengths by placing the numeric keypad and directional arrow keys to the left of the alphabetic keypad. Some left handed keyboards have the alpha keys angled similarly to an ergonomic keyboard. Another version of a left handed keyboard has a mirrored numerical pad, which is laid out in reverse of a standard numerical pad.
Even those who aren’t left handed may benefit from a left handed keyboard. The left handed keyboard can also be used by one-handed typists. Some two-handed typists find that the left handed keyboard prevents or relieves discomfort in the hand, wrist, or arm.
Those who are right-handed sometimes discover that by using a left handed keyboard, the location of the mouse is moved more to the center of the work area. By bringing the keyboard closer to the mouse, pain or discomfort caused by reaching for the mouse can be reduced. The left handed keyboard also distributes the workload more evenly between both hands. With a standard keyboard, left handed users find that they must use the right hand for the arrow keys or numeric pad, or otherwise make an awkward reach.
Many special keyboards are available for those with disabilities such as physical or visual impairments. Some are one handed compact devices that use a method called chording, which involves the simultaneous use of just a few keys.
Other specially designed keyboards eliminate the need for more than one key to be pressed at a time. These keyboards, often used by those with severe motor impairments, have larger individual keys and overall measurements. They also require only a minimum amount of pressure to activate the keys. For those who are hearing impaired, a light flashes to signify acceptance of input. For those who are visually impaired, an audible click serves the same purpose.
Many specially designed keyboards, such as a left handed keyboard or ergonomic keyboard, help reduce the risk of repetitive strain injury (RSI). RSI is sometimes caused by repetitive computer activity. Adjustable keyboards are available that divide into two alphanumeric sections that can be adjusted both horizontally and vertically. Each user can adjust the keyboard to his or her natural hand posture with this type of keyboard, thus possibly reducing the risk of RSI. The ergonomic mouse, wrists rests, and number pad and mouse platforms can also be of benefit.