access to the same applications as anyone else. Outspoken is a Macintosh application
that uses synthetic speech to make other Macintosh applications available to visually
impaired users. A common problem with this and other screen readers and talking
browsers (see Section 10.3.1) is the sheer amount of information represented.
Browsing is difficult and all of the information must be held in the head of the user,
putting a heavy load on memory.
A more recent development is the use of touch in the interface. As we saw in
Section 10.3.2, there are two key approaches to this, both of which can be used to
support people with visual impairment. Tactile interaction is already widely used in
electronic braille displays, which represent what is on the screen through a dynamic
braille output. It could also be used to provide more information about graphics and
shape, if the engineering challenges of building higher resolution tactile devices can
be overcome. Force feedback devices also have the potential to improve accessibility
to users with visual impairment, since elements in the interface can be touched, and
edges, textures and behavior used to indicate objects and actions. A limitation of this
technology at present is that objects must be rendered using specialist software
in order for the devices to calculate the appropriate force to apply back to the user.
This again represents a move away from use of generic applications to specialist
applications. However, it is likely that major applications will become ‘haptic
enabled’ in the near future.