Abstract

The visual function of ARM observers is assessed using the most comprehensive techniques by measuring their contrast sensitivity function.^1-4 The contrast sensitivity function maps out the range of visible spatial frequencies. Only patterns composed of low and intermediate spatial frequencies can be seen by ARM observers.^1-4 An ARM observer’s losses in sensitivity to intermediate and high spatial frequencies can be partially compensated for by increased magnification to aid image recognition.⁴ Too much magnification, however, will produce such large letters that only a few letters are able to be seen in a single glance. Therefore, reading performance deteriorates with too much magnification.⁵ Magnification alone is not sufficient for transmitting recognizable information to the visual cortex.⁶

© 1988 Optical Society of America