Creating Accessible Teaching and Support

Assistive technology for a person who is blind or vision impaired can assist in either supplementing or replacing the visual information that the person cannot see through:

• magnification - eg simple magnifiers that are placed on a document or computer programs and electronic devices that that enlarge an image on-screen
• voice output - screen readers use synthesised speech to "read" information on computer screens
• Braille  - tactile language of raised dots embossed onto paper or a Refreshable Braille display
  
• tactual graphics - raised lines and surfaces to re-create maps, drawings, graphs etc.

A screen magnifier is software that enlarges the image on the computer screen. It is useful for students with vision impairment with some functional vision; students with little or no vision usually use a screen reader.

The screen magnifier enlarges the cursor, and a focal point of the original screen content so that it covers the entire screen. The enlarged section is the main point of interest to the user, and as the user moves the cursor, the screen magnifier tracks it to show the new enlarged portion. Sometimes this is jerky and flickers, and this can be uncomfortable for the user, and pop-up windows and changes in system status can also cause problems.

Magnifiers range from 2x to 32x magnification – the greater the magnification, the smaller the proportion of the original screen content viewed at a time.  Some products include screen readers that "read" the text on screen using synthesised voice.

Screen magnifiers often provide other features for people with vision impairment:

• colour inversion - screen glare can be reduced by inverting text from black-on-white to white-on-black
• “smoothing” text compensates for the blocky, hard-to-read effect of some enlarged text
• modification of mouse and text cursor (such as circling it to help the user locate it on the screen)
• different magnification modes to alter how the enlarged portion is presented according to the user’s needs.

Possible difficulties include:

• stylised fonts that are difficult to read
• inadequate contrast, especially if text is over graphics
• important information that is missed because it is over to the far right or down below the screen image
• small text or images that require increased magnification
• mouse-dependent commands (while some people do use the mouse, others find that combined with magnification, using a mouse creates too much movement around the screen).

Screen reader software (such as Jaws) allows the user to hear the information on the screen via a speech synthesiser or by touch through a Refreshable Braille display. It also helps the user navigate around the document or in a Web browser to get a list of the links without reading through the entire Web page.

Screen readers can only read text, therefore images should be provided with text description (alt text).  Users of screen readers generally rely on the keyboard for navigation and cannot use mouse-dependent commands with no keyboard equivalents.  Confusing layouts such as complex tables without row and column labels and pop-up windows can be problematic.

Refreshable Braille display is an electro-mechanical device for displaying Braille characters, usually by raising dots through holes in a flat surface. It enables students who cannot use a standard computer monitor to read text.

CCTVs (closed circuit televisions) can be used by someone with low vision. The material – books, worksheets, lecture notes – is placed under the camera, and the magnified text or image is displayed on a screen.  Some systems allow the user to switch between CCTV image and word processing software on their computer.

CCTVs come in 3 main types:

• a fixed camera over a movable table on which the document is placed
• a movable camera which can be rolled over the document (some versions of this type can be interfaced with the computer allowing the user to work with computer programmes and view the enlarged CCTV image on the same screen)
• a mobile unit which can be used to enlarge text in libraries, shops or the workplace.

One system will not suit all as quite often the CCTV system used will be specific to that person’s requirement.  Contrast, colour, magnification and capacity to access a split screen are just some of the parameters that may differ between systems.

• Additional space and access to power points for the equipment will be required at any work station including examination/assessment facilities.
• Electrical cords across floors may potentially be a hazard.
• Seating arrangements within the learning setting may need to be adjusted to accommodate the equipment.
• Providing course materials (eg. notes, handouts, charts and diagrams, readings etc.) to the student prior to the class/session/practical will assist their preparation for the class as they will have the opportunity to pre-read the information.  
• The print quality of written materials remains important as many CCTV systems cannot legibly magnify pencil and light computer printouts.
• Due to their impairment, some students may only be able to effectively use their CCTV system in a darkened environment.