A trackball is a control instrument for entering commands. It is mainly applied in specialized areas. Trackballs are used for example in the medical, shipping as well as in manufacturing and trading industry. In addition to the name-giving ball, which can be made of plastic or stainless steel, trackballs have two separately placed buttons, that are similar to mouse buttons, especially concerning their function. The buttons are usually embedded within the surrounding surface. Movements are detected by optical or optomechanical sensors. This is also similar to the functioning of a computer mouse.
Compared to the classic computer mouse, the control via a trackball has several advantages. Trackballs enable the cursor to be controlled on user interfaces without any movement of the hand. Because trackballs are fixated, they also provide very precise, smooth control, especially in harsh or moving environments.
Trackballs are often applied on firmly structured user interfaces where the available space is used as effectively as possible. As a part of the application, they are also much easier to seal against environmental influences such as dust or water. Since the hand is still during the movement of the ball, a trackball is suitable for use in cases of health problems such as tendonitis or carpal tunnel syndrome.
Mouse-trackball hybrids are available in left- and right-handed versions, with the position of the trackball on the thumb side. The mouse’s body does not have to be moved to move the cursor, as this function is performed by the trackball.