Adapting a computer for low vision users
Magnifying the computer screen
A computer screen is easy to customize to suit individual preferences and offers extensive control over presentation of text size, style and colour. This enables the user to select the most comfortable colour background, text colour and typeface. The operating system and other software on the computer also provides other opportunities for customisation.
The mouse pointer, for example, can sometimes be difficult to see for someone with sight problems. There are features within the operating system of a computer which enables the user to slow down the pointer or increase the size. If the accessibility features of operating system aren't enough other specialist software is available to enlarge the text, menus and icons on the screen.
Customising the operating system
The most common operating system is Microsoft Windows, either Vista or the older but still common XP version. There are several screen enhancement features integrated within Windows. These can be altered to improve visibility for partially sighted people. These features include pre-set high contrast colour schemes, larger standard fonts, modifying the screen resolution and improvements to the visibility of the mouse pointer and cursors. Some of these options can be modified using the control panel on your computer.
Enhancing the mouse pointer
The mouse pointer can often be difficult to see, which provides additional difficulties. There are however utilities available which can customise the mouse pointer to the users preference. Options may include:
larger pointers
colour pointers
interesting shapes or animated pointers
mouse trails which leave multiple images on the screen to highlight the movement of the mouse
a locator which gives a visual indicator of the position of the mouse
features which can automatically move the mouse pointer on the screen to a default button.
Screen magnification software
Because screen magnification software increases the size of the image displayed on the screen, only a portion of the original screen image can be seen at one time. Normally, the screen magnification will automatically follow the focus of attention, so that the area around the cursor, mouse pointer or highlighted menu item is magnified. Moving the magnified window in order to view other parts of the original screen image is done by using the mouse. Some screen magnification programs now provide supportive speech output as well. The contents of Word documents, menu items and icons are usually spoken using the computer’s sound.
Other features that may be available in a magnification package may include:
Smoothing jagged edges of characters at higher magnifications
Altering the colour of text, foreground and background
Changing the size and appearance of the mouse pointer and cursors
Using different sizes and shapes of magnified windows
Continuously magnifying a particular area of the screen
Customising which on-screen events are tracked by the magnified window, and which are not.
Adapting the screen
Fresnel lens
Fresnel lenses are plastic sheets that can be placed in front of the computer screen, and offer small levels of magnification. However optical quality is poor compared with the sort of magnifiers commonly used to access print. The same magnifying effect may be achieved simply by moving closer to the computer monitor.
Anti-glare screen filters
Glare from a computer screen can be prevented by repositioning the screen so light from a window or from an overhead light does not reflect onto the screen. High quality anti-glare filters for computer screens may help, as long as the contrast or the brightness of the screen is not compromised. These are standard office items, but attention should be paid to the type and quality of filter if it is to be used by a partially sighted person.
Making the keyboard easier to see
Keytop stickers / keyboard glove
Keytop stickers are self-adhesive stickers, which can be stuck onto individual keys on the computer keyboard. The lettering on the stickers is large and printed in a bolded typeface with black lettering on a yellow background, white lettering on a black background or black lettering on a white background. Large print flexible keyboard gloves which fits over any make of keyboard are also available in the same colour options as the stickers.
Large print keyboards
There are two large print keyboards available. There is a standard size keyboard available with large print on the keys, which is 400% larger letters compared to standard keyboards. The keyboards are available in black letters with white or yellow background and white letters with black background.