Perceptual Impairments: New Advancements Promoting Technological Access
The introduction of early computers facilitated new ways for individuals with visual impairment to access information electronically: magnižed, in Braille, or aurally via the conversion of digital information. However, the introduction of graphical user interfaces (GUIs) that present digital information via visual metaphors and icons contributed to the digital divide, which can hamper the productivity of this population. In many cases, even access to documents and forms can be a difžcult to impossible task when available through the direct manipulation paradigm (Fortuin and Omata 2004). The exclusive reliance of GUIs on the visual interaction paradigm therefore threatens to limit accessibility for anyone whose visual channel is compromised (Dix et al. 1998). This chapter provides readers with (1) an introduction to the visual sensory channel; (2) a review of research approaches, models, and theories that are relevant to human-computer interaction
(HCI) and visual impairment; and (3) a discussion of forms of visual dysfunction in the research, design, and evaluation of human-computer systems.