Many people with serious visual impairments live independently, using a wide range of tools and techniques. Examples of Assistive Technology for visually impairment include the Canadian currency tactile feature, which a system of raised dots in one corner, based on Braille cells but not standard Braille. For general computer use access technology such as screen readers, screen magnifiers and refreshable Braille displays has been widely taken up along with standalone reading aids that integrate a scanner, optical character recognition (OCR) software, and speech software in a single machine. These function together without a separate PC.