|1 University of Wisconsin -- Madison, firstname.lastname@example.org|
|2 Bascom Palmer Eye Institute - University of Miami School of Medicine|
|3 Florida International University|
Visual icons are standard features of graphical user interfaces (GUI). Visual icons employed during human-computer interaction (HCI) are in the form of pictographic symbols that represent relationships between attributes of real world objects and functions within computing systems ( Gittins, 1986). Icon use requires a pointing device, most frequently a mouse. When using a mouse, two interaction tasks are critical to successful icon activation: selection and position ( Foley, Wallace & Chan, 1984). In selection tasks, the user chooses from a set of items displayed on the screen. In position tasks, the user chooses a point in a one- two- or three-dimensional space. Completion of these tasks requires complex interactions of the human visual and motor systems. Successful use of iconic representations within GUIs places considerable demands on the human visual system.
While the HCI knowledge base is rich with respect to the design and use of visual icons for "normal" users, little data currently exist that characterizes the interaction strategies of computer users who are visually impaired. Researchers have shown that tasks requiring iconic selection are problematic for low vision computer users due to reduced visual acuity, contrast sensitivity, visual field and color perception. The implications are longer visual search times and reduced accuracy ( Jacko, Dixon, Rosa, Scott & Pappas, 1999). Based on these findings, we hypothesized in the current research that visual impairment would increase movement time and decrease accuracy during the positioning of a mouse cursor on visual icons.