Sign at left is most legible.

Signs are often seen from an acute angle. To make things worse, they are often seen in less than perfect lighting levels. This photo helps show what different safety sign or label headers look like to someone with less than perfect vision? How does it appear when you approach the sign from an angle, or in low light? Using a technique pioneered for evaluation of highway signs, Dr. Kline studied sign headers as approached at an angle of 22.5 degrees with 20/50 vision and low light. Dr. Kline writes, "Oblique viewing angles reduce legibility markedly, in part because of the horizontal reductions in letter width and inter-letter spaces. For example, the effective viewing width of a real label is reduced from about 7" straight on, to 5" at 45 degrees and to only 2.7" (or to 1/3) at 22.5 degrees. The acuity/luminance problem noted above is very much exacerbated by such horizontal crowding (e.g., see the "NIN" letter sequence in "WARNING")."

The SmartSign Clearview® font was specifically designed to help overcome many of the troubles shown with other sign type fonts.