An instrument is described with which one can measure the course of human visual dark adaptation under specified but flexible conditions useful for physiological and clinical investigation.The preadapting light adaptation is controlled in brightness, retinal location, and duration,and the subsequent dark adaptation of a specific retinal area is measured with light flasheswhose spectral composition and duration are controlled.
SELIG HECHT and SIMON SHLAER, "An Adaptometer for Measuring Human Dark Adaptation," J. Opt. Soc. Am. 28, 269-269 (1938)