The Technology For Visually Impaired Computer Science Essay

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The particular area of technology which focuses on enhancing the ability of the disabled people is known as assistive technology. Apart from ensuring independence, security and productivity for the disabled it also helps them in achieving positive identity and self esteem. The technology assists the disabled people in their employment and thus enables them to have an independent living. Despite the recent advancement in the assistive technology, one third of the technologies are abandoned after the initial use. This is because it failed to meet the user requirements and expectations (Mehdi, 2006).


As mentioned in an article Disability and Society, various visual assistive technologies which includes both hardware and software, are available which provides sight enhancement or sight substitution mechanisms for the computers and mobile phones. A few of which are as described below

For partially sighted - A screen magnifier software application is used which magnifies the screen display so that the persons who are partially sighted could read texts, select menus or could navigate effectively between different websites.

The software runs as a background task enabling the user to enlarge the texts and the graphics over a wide range of levels.

Blind persons - The assistive technology for the blind involves non visual alternatives that could convert the visual interface to tactile or auditory output or the combination of both. The most common technology used is an electronic Braille display which produces a line by line tactile output on a special keyboard. The disadvantage of this instrument is that it gives a text based output and does not interpret graphics. However an alternative is a screen reader which interprets the text as well as the graphics into an auditory output.

Other technologies for the visually impaired persons include (AFB, 2011)

Video magnifiers - The video magnifiers include a CCTV camera which would be either hand held or stand mounted and the device would magnify and project the image to a monitor.

Stand alone products which are specially designed for the blind persons such as PDA's (Personal Digital Assistants) and electronic book players which provide access to books, messages, appointment calendars, phone numbers etc.

Braille embossers which convert the text into hard copy Braille.


A person who is hearing impaired won't find much difficulty in operating the computer except for the operating the files with sound. He requires assistance in communication. The hearing impairment might be either mild hearing loss or total hearing loss. According to a background paper by Virginia the assistive devices for both of them are given below

Auditory speech processing aids - It's a device which can either increase or decrease the frequency of the speech signal

Infra red amplification systems - These devices are often installed in the theaters and enable the hearing impaired to listen without using the hearing aids. A receiver brings them clear, strong sound directly from stage

TDD (Telecommunication device for the deaf) - Earlier it was called Teletypewriters. It is a device which allows the hearing impaired/speech impaired to communicate over the telephone. It is installed in universities and a few offices.


There are a wide variety of sub categories for the physical disability. The assistive technologies that should be adopted for each of them would be different. In general people with the physical disability may not be able to

perform a spontaneous limb movement

have a proper coordination while walking

write or type

carry out tasks which require strength

move around independently

take stairs

do certain tasks such a turning a door knob, keys etc

The requirements for the person with a physical impairment may begin with a mobility aid like a wheel chair or motorized scooters. The mobility aid is further modified by adding certain assistive technological solutions like an adaptive keyboard, a communicative aid, and special switches to control it.

The most common communicative aids are the following (GAWDS, 2009)

Access/Ability switches - It utilizes the controlled movement from a foot, head, eyeblink or breath. It is possible to use a number of switches simultaneously depending on the software. The operation of the switch may vary according to the requirements. The pressing of it or letting go may trigger it. The device is time consuming and like most of the AT's it is frustrating for the user as well as listener.

Ergonomic keyboards - It's a specially designed and shaped keyboard which cut shorts the motion required for typing thus reducing the pain and effort required for typing. The features include two way tilts, inbuilt wrist rests, split angle key layouts. Three different designs includes single handed keyboards for the people with only one hands, single finger/head/mouth stick keyboards for people who do not have the use of a full hand, expanded keyboards for physically disabled and visually impaired users.

Portable keyboards - It's a small battery operated keyboard with display and memory storage. It could be used when they could not access a standard work station.

Another specialized communication device was designed for the physically disabled people which mainly consists of a Multimodal Interface Adaptor (MIA) employing a voice recognizer, pointing device, a text composer for sending e-mails and an application software. (Anogianakis, 1997). The personalized speech detection includes a word spotting function. The function has the capability to extract command words from the user and avoids the extraneous comments such as " Ummm", "Ahh",etc. The text composer allows the user the sent e mails by using the voice recognition system. The document scenario files in the text composer are structured in sentence frames. The database is composed of tree structures with words to generate sentences. A sample text database for an e-mail is as shown in the below figure.

tree 3.jpg


A learning disability is the difficulty faced by a person in taking in information and processing it in the brain. This is due to a dysfunction in the central nervous system. This disability fall within four categories as given below (SC, 2011),

Spoken language - difficulty in listening and speaking.

Written language - difficulty in reading, writing and spelling.

Arithmetic - difficulty in calculation and concepts.

Reasoning - difficulty in organization and integration of ideas and thoughts.

Some students have one or more than one of the above difficulties. The hard fact is that, to an external person the person with this disability might seem to be lazy or not trying hard enough. It is to be understood that not all the technologies are appropriate for all people. People have different strengths, weakness, tastes etc. The technology which suits one person may not suit another person. (FROSTIG,2000)

The following are the different types of assistive technologies used (GREATSCHOOLS, 2011)

Abbreviation expanders :- It's a software designed for the people facing difficulties in writing. It's used with word processing and it allows the user to create, save and reuse the abbreviations of the commonly used words and phrases and also ensures that the spelling of it is correct.

Alternative keywords :- The specially customized keyboard benefits people who has difficulty in writing. The programmable keyboard has less input choices, keys grouped by color/location, and certain graphics added to it.

Audio books and publications :- Recorded books made available in the electronic format. A search option and an option to bookmark pages and chapters are also included. It benefits people who struggle with reading.

Electronic Math worksheets :- It helps students in organizing, aligning, and working through math problems on a computer screen. Speech synthesizer option is also available which reads the numbers appearing on the computer screen aloud. The software benefits people who struggle with math.

Freeform database software:- This works in conjunction with word processor and enables the user to jot down any information on any length on any topic and later access it by typing any fragment of the original note. The software benefits people who struggle in organizing and memorizing.

Graphic organizers and outlining :- The software organizes the information fed by the user into appropriate categories and order.

Information/data managers:- They may be portable hand held devices or softwares or combination of both that is used to plan, organize, store, and retrieve his calendar, task list, contact data, and other information. The tool benefits people struggling with organization and memory.

Optical character recognition:- The device is used to scan the text, store it and then read it aloud using the speech synthesis/screen reading system. It benefits people struggling with reading.

Personal FM listening systems:- It consists of a wireless transmitter with microphone and a receiver with earphone. The words of the speaker wearing the transmitter is transmitted directly to the listeners and thus helping him to focus.

Proof reading software programs:- It's a software which scans the users written work and report the errors (errors in spelling, grammar, punctuation, word usage, and sentence structure)

Speech recognition systems :- The software work in conjunction with word processor. It recognizes the spoken words of the users fed through a microphone and converts it to a text.

Speech synthesizers/Screen readers:- It reads aloud he text input in the computer to the reader. It benefits the people who are struggling in both reading and writing.

Talking calculators:- The calculators which read aloud the numbers, operation done and the answers. The audio feedback allows the user to cross check the operation done and verifies the answer.

Talking Spell-checkers/Electronic Dictionaries:- This tool is for those persons who struggle with spelling. Enables the user to select or identify appropriate words and correct spelling errors during the process of writing. The device reads aloud and displays the selected words on screen.

Word prediction software programs:- The software predicts the word that the user intend to write. The prediction is based on spelling, syntax, and frequent/recent use.


The advancement in the technology, assistive technology has enabled the disabled people to get employment along with their able-bodied colleagues. The development in mainstream technologies has enabled people with physical impairments who find it difficult in accessing and manipulating the paper documents. The operating systems for the computers are constantly been updated to be more user friendly. The internet, emails, online scheduling and mobile phone has enabled them to increase their workplace effectiveness. Moreover with the advancement in the information technology as a whole has allowed flexibility in the place and time for doing the work benefited the persons with some physical disabilities. Again the development in the mass- market technology has introduced specialized technologies like voice recognition software for the disabled people for communication, computer access and mobility (Desleigh, 2006).

There is a vide variety of specialized technologies used in the work place for the disabled namely(ENABLEIRELAND, 2010),

Voice Recognition Software :- It enables the hand free use of computer. This software allows people to use their voice for sending emails, saving files and surfing the web.

Visual support software:- The software is designed for people with visual impairment. It magnifies the screen for the low vision users and screen reader reads out the text in the computer screen for the people who have no vision.

Switch accessible software :- The people who could not use a standard keyboard has an on-screen keyboard and they allow the user to select the keys using an alternate mouse, switch or Morse code system.

Alternate mouse :- This includes Joystick mouse which allows the user to move the cursor by moving the joystick , Touchpad - pointing devices, head mouse - a reflector dot being placed on the user's glasses/forehead, foot mouse - use of feet instead of hand.

Alternative input devices - The devices which are used to control the computers without using the standard keyboard or mouse. These include customized parties, head operated pointing devices, head and foot operated mouse, control switches.

The US department of defense has introduced a program called Computer/Electronics Accommodation Program (CAP) to assist the disabled get employment. The CAP encourages federal agencies to hire employees having long term disabilities. The technologies promoted through this program include speech-recognition software for people who have trouble using a keyboard, computer screen magnification programs for people with visual impairments, and talking dictionaries for people with cognitive disabilities, screen-reading software, that print the text of a screen in Braille (PCWORLD, 2011).