Aids for people with blindness and visual impairment

Operating computers, using the Internet, reading content and finding your way around are key requirements for independently obtaining information, communicating and being on the move. Modern information and communication technologies and digital media can be used to support the equal participation of visually impaired and blind people in school, work and social life.

For a compact overview, exemplary assistive product types with a focus on computer hardware and software as well as electronic aids are described here.

The range of technical aids is wide, but some product features are typical or worth mentioning, such as

  • large numbers or letters
  • large, illuminated displays (displays)
  • Voice input and voice output
  • tactile marking points (Braille)
  • Guide lines and edges
  • Two-sense principle of accessibility (acoustic and vibrating / tactile alarm signals)
  • Ultrasonic or GPS (Global Positioning System) for orientation
  • RFID technology (Radio Frequency Identification) for labelling or product recognition

Braille printer (dot matrix printer)Braille printers punch the Braille or graphics on special paper. The braille paper is much thicker and more robust than conventional paper for common printers. This makes information perceptible and therefore readable for people who are blind and who have mastered Braille. A special conversion software converts files into the Braille character set. There are double-sided printing Braille printers with continuous paper or small, handy Braille printers with single sheet feed for mobile use.

Braille displays: Braille displays output the screen contents in Braille braille for the blind, which can be felt with the fingertips by means of pens of different heights. The displayed section can be moved and corresponds approximately to an A4 line. A screen reader is required as a bridge software between the output medium and the computer. Mostly a combined voice output on the computer is also used. With a Braille display one can usually only read the screen contents but not enter any data. Larger, 80-digit Braille displays are suitable for stationary workplaces, whereas smaller and mobile Braille displays with 12, 20 or 40 modules are preferably used for mobile working, for example with a notebook.

  • Braille notebooks: Braille notebooks are smaller devices for mobile use. They are equipped with voice input and output as well as Braille input and output, alternatively with a laptop keyboard for text input. They have the usual interfaces and data connections as well as a standard operating system and can be synchronized with the PC system.

Reading systems (character readers, reader-readers)Reading systems scan paper documents such as books, articles or invoices and store them in a file. A text recognition software (commercially available OCR Optical Character Recognition software or special scanner software for blind people) processes the data, which is then played back by the voice output. Optionally, the person can also read the text with a Braille display or print it out in Braille if a dot matrix printer is also connected to the system.

A distinction is made between closed and open systems:

  • Closed reading systems are compactly manufactured devices that contain all components from scanner, text recognition software to voice output. The functions are distributed over a few, easily palpable control elements and are therefore easy to operate. The output is done by voice output or Braille display. Some closed devices save the scanned texts. Closed reading systems are especially suitable for people who will be blind later on and replace the use of a computer.
  • Open reading systems are usually used at the workplace on a standard PC in combination with a scanner, text recognition software and the reading software. In contrast to closed systems, open reading systems output the scanned documents only by voice output. The data can be stored and processed with conventional word processing programs. The system can be controlled via the computer keyboard.

Large character keyboards: These keyboards for visually impaired people have high-contrast and larger inscriptions and some have tactile markings.

Monitors: Large monitors with a screen diagonal of at least 20 inches and high screen resolution (display size of the pixels) are important for people with visual impairments, especially if they use magnification software. In addition to monitor size, brightness and contrast, mirroring properties and adjustability to personal requirements are important.

Screen readerThe screen reader is a complex screen input and output software that controls screen contents. The software interprets the screen information (e.g. texts, graphics and their meaning, the current input position or the screen layout) and outputs it tactilely via Braille displays or acoustically via voice output. There is external screen reader software installed on the PC (e.g. JAWS) as well as integrated screen readers. TalkBack, for example, is the screen reader from Google on Android devices, VoiceOver is built into iOS devices. Screen readers also help to use large parts of the standard software independently. However, not every computer program can be operated with a screen reader, for example due to poorly adapted software. Application training is therefore recommended.

Enlargement software: For people with visual impairments, there is screen magnification software that not only displays screen content larger, but also enhances contrasts and colours and tracks focus (e.g. ticker, document reading function). Various output media (e.g. voice output, Braille display) can be combined with the software. The information not visible in the enlarged image section is thus available, which relieves the eyes.

Voice output: Voice outputs read text on the PC screen aloud. A voice output is an integral part of a reading system or screen reader, which enables orientation on the screen. Speech speed, volume, tone pitch and sentence melody can be individually adjusted. There are voice outputs as stand-alone software (e.g. for converting text on the computer screen or display of a smartphone into speech, reading aloud SMS and e-mails on a mobile phone). These standardized announcement and read aloud functions are not developed specifically for people with visual impairments, but are often intended for mobile use (e.g. drivers).

Text and object recognition software (character reading software): Text recognition software (often called OCR software - Optical Character Recognition) identifies letters in a document or in graphic files such as PDFs, photos or scans and converts them into digital text files. The text files can be further edited or copied. The text files are usually output in combination with computers and mobile devices via screen reader software (e.g. voice output). Usually scanners (e.g. flatbed scanners) transfer the text documents. Smartphones are also suitable for occasional scanning. In contrast, object recognition software compares photos or codes such as barcodes with a database and outputs the descriptions stored for this purpose. This makes it possible, for example, to recognize products and sometimes faces.

Voice recognition softwareA speech recognition software can automatically convert speech into text that appears directly on the screen. The speech recognition software can also be used to control computers and other devices. However, depending on the degree of visual impairment, speech recognition is only useful in conjunction with other aids such as Braille displays, screen readers, magnification systems or speech output. Mobile devices with the Android and iOS operating systems have their own integrated speech recognition.

Apps: For mobile devices such as smartphones or tablets, there are numerous, often pre-installed apps (applications for small displays and touch screens), which are also helpful for people with visual impairments and blindness. Examples are apps for the recognition of texts, barcodes, colors, light or banknotes. Native apps are tailored to the computer's operating system (e.g. iOS, Android). Web apps run platform-independently in the respective Internet browser and should support the other required tools (e.g. screen readers) well. In our App Search you can search for other apps in the App Store (iOS) and Google Play (Android).

Other software for people with visual impairment: Other special software programs for people with visual impairment can only be operated using the keyboard via direct input commands and menus. The range of software includes accessible currency converters, e-mail clients, accessible database software or management programs for electronic files and other document management systems.

Magnifying vision aids support people with visual impairments in reading and spatial orientation when glasses or contact lenses are not sufficient. However, as the magnification increases, the displayed image section becomes smaller.

Optical vision aids: Optical visual aids enlarge information on paper or displays at close range and at long distances for people with visual impairments. They are mostly used when the magnification and contrast requirements are not so high and when reading shorter texts. Depending on the design, up to 12x magnification is possible.

  • Optical visual aids for the near fieldThese include magnifiers, magnifying glasses and lenses. There are, for example, magnifying glasses and stand magnifiers with illumination or large screen magnifiers that are placed in front of a TV screen. Display glasses for the workplace are adapted visual aids for computer activities when normal reading or progressive glasses or contact lenses do not meet the visual requirements. The distance to the monitor is adjusted to about 50 to 70 cm for screen glasses. Often the employer pays the full cost of the monitor glasses within the scope of his obligations under occupational health and safety law.
  • Optical visual aids for the long distance rangeThese are for example binoculars, telescopes and telescopic glasses. Telescopic glasses or monoculars (pocket telescopes) make it easier to find your way around in unfamiliar surroundings (e.g. reading road signs or display panels from a greater distance). Telescopic magnifying glasses (telescope glasses with clip-on magnifier) can facilitate reading.

Electronic visual aids: Electronic visual aids enlarge information from paper documents or writing tablets on stationary or mobile devices. Often they are able to display different contrasts (light-dark, colour) and in some cases also text recognition, making them suitable for people with severe visual impairment. Depending on the model and monitor size, magnification of 5 to 60 times is possible.

  • Screen readersElectronic screen readers, also known as camera reading systems, record text excerpts (e.g. documents, books) and transfer them to a screen at a high magnification. They can also be useful when contrast is required. Screen readers are available for close-up and/or long-distance use (with a long-distance camera), for example for recognizing the contents of PowerPoint lectures or on blackboards. A distinction is made between stationary, transportable and mobile, small screen readers.
  • Electronic magnifiers: Electronic magnifiers are battery-powered, pocket-sized screen readers for mobile use. They magnify much more than optical hand magnifiers.

Cordless landline and mobile phones (cell phones): Landline and mobile phones adapted to the sensory impairment have, for example, tactile large keys, high-contrast displays, memory functions for direct dialing, voice control, screen readers for voice output or output via a connectable Braille display, and magnification software with the option of connecting Braille displays. The software must be compatible with the telephone device.

SmartphonesSmartphones correspond to small computers with which one can make phone calls. They offer a variety of pre-installed or optional operating aids such as zoom function, screen reader, voice output or text recognition. You can find out more about the accessibility of mobile phones and smartphones here.

Audio Players (DAISY Player)DAISY is the worldwide standard for navigable multimedia documents (Digital Accessible Information System). DAISY players can play audio files such as DAISY audio books in compressed mp3 format or read documents such as newspapers. The devices are equipped with voice output and offer navigation and setting options so that you can scroll, jump to chapters or adjust the reading speed. As an alternative to DAISY players, you can download free software to your computer and listen to DAISY content. An overview of libraries for the blind with Daisy books can be found here: Media Community for the Blind, Visually Impaired and Reading Impaired

Electronic reading devices (e-book readers): Digital books (e-books) can be read with e-book readers. The devices are easy to use, have a large memory capacity and various help functions such as glare-free displays, zoom functions and, depending on the model, built-in voice outputs.

Electronic orientation aids (navigation systems)These are devices or apps that recognize obstacles and signal the planned route and geographical location acoustically by voice output. Depending on the type, there are navigation systems with ultrasound, laser and the satellite-based Global Positioning System (GPS).

Canes for the blindThe cane for the blind (white long stick) supports tactile orientation on paths and in buildings. The tip of the cane senses unevenness and obstacles such as curbs or stairs. In order to use the cane for the blind, mobility training, usually financed by the health insurance company, is required.

Working lights (low vision lights), which are glare and flicker-free, can improve visual acuity, contrast perception and reading speed, especially during long periods of screen activity. The standard illuminances (expressed in lux) should be at least 50 to 100 percent higher for visually impaired people. When selecting light, the light colour is decisive, depending on the visual impairment. The perception of light colour is influenced by the colour temperature, i.e. the lower the colour temperature (measured in Kelvin), the higher the red component in the white colour and the light is perceived as warmer than a white with a higher colour temperature and correspondingly higher blue components. Luminaires with colour temperatures similar to daylight reach a value of over 6000 Kelvin.

Status: 2019