Understanding the Effects of Visual Impairment on Visual Search

The effect of vision loss on visual search has been extensively studied in psychology, but little is known about the relevance of these insights to human-computer interaction (HCI). This paper takes a first step towards a user model of visual impairments. Variants of the model are used to explain how people with Age-related Macular Degeneration (AMD), glaucoma or cataracts search for visual information on a computer display. The model formulates the visual search problem as a reinforcement learning (RL) problem. It is tested on its ability to predict the effects of visual impairments on how people search for objects in a crowded display or within a wide visual field. We discuss how the model might help the design of more accessible user interfaces and enhance user experience for those with vision impairments.