The writer believes that the reported reduction in time necessary to dark-adapt the eyes by wearing red goggles for a period of approximately 30 minutes is due to the much reduced brightness of the visual field as viewed through the goggles and not to the wave-length region involved. Data are presented to show that a comparable effect is secured when neutral rather than red filters are used to screen the visual field.
EARL M. LOWRY, "The Effect of Hue on Dark Adaptation," J. Opt. Soc. Am. 33, 619-619 (1943)