The ability to read electronic small visual displays (SVDs) affects successful functioning at home and in the workplace. SVDs can be found in products as diverse as cell phones, office equipment, home appliances, and home medical equipment. Individuals with vision loss face severe limitations in using such products safely and effectively because the visual displays often utilize inexpensive display technologies and poor design choices which make them difficult to read. lack accessibility features. A usable SVD is extremely important to the more than 25 million who report having vision loss.
The "readability" of an SVD depends on two aspects – the ability of the visually impaired person to discern details and the ability of the screen to generate them. These two aspects can be quantified. The American Foundation for the Blind (AFB) has been creating means to assess SVDs (a) by developing optical instrumentation to measure these displays and (b) by conducting a study to correlate display measures with display recognition ability of persons with vision loss in conjunction with the Palo Alto VA.
Building on this past research and with support from the Department of Education's National Institute on Disability and Rehabilitation Research, AFB has undertaken a project with three sets of outcomes: (1) a replicable, and potentially commercializable, Optics Lab for measuring SVDs; (2) a set of guidelines for the design of SVDs relative to human contrast sensitivity function which will be commercially valuable for product developers; and (3) an online database which will provide information on the accessibility and usability of a minimum of 250 products with SVDs.
The AFB TECH Optics Lab is designed to measure display qualities of all types of SVDs. The lab uses a custom-built sampling sphere to illuminate the display and a digital camera to take a high resolution image of it. The picture is then sent to the dedicated PC, which uses image analysis software to measure multiple display characteristics, including: contrast, reflection, and spatial frequency. These measurements are then used to calculate the Square Root Integral (SQRI) of the display, which is an image quality metric that combines display measurements with the Contrast Sensitivity Function (CSF) of a user to predict whether a person will be able to read the information on a specific display. . This information will be put into a format for consumers and manufacturers to easily compare the low-vision accessibility of hundreds of devices currently on the market. The AFB TECH Optics Lab equipment and some key AFB personnel are shown below.
This is a development project and more. It is a systems change project, an accessibility project, an advocacy project, and an information dissemination project. The intent is to establish a market environment in which manufacturers – now and in the future – compete to improve accessibility and give consumers a choice of SVDs that best match their visual abilities. The project will build on AFB's strong history of technology awareness and expertise, mission synchronicity, and reputation for collaboration and advocacy. Through its AccessWorld e-zine, AFB transmits results of specific product testing directly to 8,000 readers who, as sophisticated consumers, are access technology advocates. AFB has many successes in transmitting similar information to manufacturers and getting product modifications in next-generation products.