Rating visual capability for computer access with a fuzzy rule-based model

Visual impairment is a loss of vision that makes it hard or impossible to perform day-to-day activities, and is considered to be one of the most feared disabilities. People who have low vision or are blind often rely on assistive supports when using computers, since a standard computer system may not provide the appropriate needed support. A comprehensive assessment of the user's visual abilities is essential in determining the most appropriate combination of user interface devices and software. A user's visual capability can be assessed by measuring acuity with the Snellen or Baily-Lovie charts, contrast sensitivity with the Pelli-Robson chart, color perception with the Ishihara or Farnsworth D-15 tests, field of vision with projection perimetry techniques, and tracking and light sensitivity by clinical observation. This paper presents a novel architecture for a fuzzy rule-based expert system that can rate visual capability of individuals with visual impairments for computer access.