ROD AND CONE CONTRIBUTIONS TO MESOPIC VISION

摘要

Mesopic light levels span approximately 3-4rnlog units in the natural viewing environment,rnincluding many indoor lighting settings, andrnmost twilight or nighttime outdoor and trafficrnlighting environments. Traditional studies ofrnthe contribution of the differentrnphotoreceptor types to mesopic vision havernbeen hampered by an inability to modulaternthe rod or cone systems independently. Ourrnapproach differs from the traditional studiesrnin employing a four-primary method thatrnallows independent control of the stimulationrnof the four receptor types in a stimulus field.rnWe developed a general method forrnadjusting the radiances of four lights tornsilence up to three photoreceptor classesrnand change the excitation of the nonsilencedrnclasses in a specified manner. Here, werninclude an overview of rod anatomy andrnphysiology and a description of the logic andrnimplementation of the four-primaryrnmethodology. Data and analysis are givenrnfor two functional areas that may impactrnlighting solutions; dark-adapted rodsrnsuppress cone vision, and how rod andrncone reaction times vary at scotopic,rnmesopic and photopic adaptation levels.