Physical parameters that influence the legibility of an instrument panel display include letter/graphic size, the luminance and color difference between graphics and background, the observer's luminance adaptation level, and the level of glare present. Several aspects of visual functioning deteriorate as part of the normal aging process. These include a reduction in luminance and color contrast sensitivity, an increase in sensitivity to glare, a reduction in visual accommodation capacity, and a reduction in the sensitivity to light. This SAE Information Report provides introductory information that should be considered when setting photometric guidelines for instrument panel displays that are designed to accommodate the older driver. More detailed information is provided in Section 2 of this document.