Selig Hecht was a researcher in the physiology of vision who measured how sensitivity changes during light adaptation and dark adaptation. In a 1937 study, Selig Hecht and colleagues varied prior illumination and then measured recovery of the human eye's ability to detect faint test lights.[ref]
The influence of light adaptation on subsequent dark adaptation of the eye by Selig Hecht and others. Original byline and Abstract: preadaptation and recovery measurements
The recovery curve depended on the preceding exposure. Under sufficiently bright preadaptation, an early phase associated with cone cells was followed by a slower phase associated with rod cells; other exposure conditions did not reveal both phases in the same way.[ref]
This makes prior conditions part of the experiment. Two observers tested after the same time in darkness need not be in comparable states if their preceding illumination differed. A curve measured over time reveals changes that a single final sensitivity measurement would hide. The historical illumination unit called photons in this paper should not be interpreted as a count of individually detected photons.
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Selig Hecht is a prominent figure in the field of optics. He is known for his contributions to the understanding of light and its properties. He made significant advancements in the study of optical materials and systems, influencing both theoretical and practical applications in optics. His work may encompass areas such as lens design, image formation, and optical measurements.