Newer generations computer mouse illuminate the surface on which the mouse is moved with a built-in light source, such as a light emitting diode and take the reflection an optical sensor.
A built-in microprocessor calculated from the differences between images taken in sequence direction and speed of movement of the mouse. Problems caused by dirty balls and especially roll axis can no longer occur by design but can be resolved by Apple repairs in Sydney. Sometimes the optical signal at fine movements is misinterpreted on well-structured documents and the pointer moves wrong.
The first mice of this type required special mousepads on which a grid or points were recorded at which the optical sensor was oriented.
With higher performance of the built- in microprocessors computationally intensive algorithms mice can be used for image processing today. That is how modern optical mice on almost all source documents.
Only areas that have very little or no structure, such as mirrors, glass and many painted surfaces are inherently unsuitable. The high precision of modern optical mouse has a positive effect particularly in graphical applications and in computer games.