Modeling Mesopic Vision Based on Measured Photoreceptor Sensitivity

A series of seven experiments were conducted under the HBCUMI grant from AFRLRHDO to study brightness, contrast acuity, contrast sensitivity, and color appearance across the mesopic range between full photopic and full scotopic vision. The transition from cone to rod inputs was measured for each dependent variable and the relative contributions of the l-cones, m-cones, and s-cones were measured for each dependent variable across the mesopic range. The data consistently show the decrease in importance of the l-cones and the critical importance of s-cones in the mesopic range. These data can inform decisions about aircrew safety in mesopic conditions and specific suggestions are offered for color appearance modeling.