Adjustable Typography For Low Vision Reading

A. Arditi

Lighthouse International,
111 East 59th Street
New York, NY 10022, and
Mars Perceptrix Inc.,
84A Furnace Dock Road,
Croton-on-Hudson, NY 10520,
USA

Purpose

The most significant limitation experienced by most visually-impaired individuals is reduced ability to read. Magnification helps, but there are costs associated with high magnification levels, including reduced visual span and navigation difficulties. Since typography affects legibility, judicious improvements in typography may reduce magnification requirements and result in better reading performance. Earlier studies have shown that varying letter spacing, stroke width, letter aspect ratio, x-height and serifed vs. non-serifed letter forms can have a significant impact on font legibility.

We have developed a computer program that allows a visually-impaired reader the ability to customize a font for best legibility, with continuous adjustment of all the above parameters (and a few more). With a text sample on the screen available for subjective evaluation of legibility, the reader adjusts each parameter by means of sliders and keyboard controls. The final adjustments may be saved in the form of a TrueType font that can be printed or viewed using other standard software.