Role of extrinsic noise in the sensitivity of the rod pathway: rapid dark adaptation of nocturnal vision in humans

摘要

Rod-mediated 500 nm test spots were flashed in Maxwellian view at 5 deg eccentricity, both on steady 10.4 deg fields of intensities (I) from 0.00001 to 1.0 scotopic troland (sc td) and from 0.2 s to 1 s after extinguishing the field. On dim fields, thresholds of tiny (5') tests were proportional to root I (Rose-DeVries law), while thresholds after extinction fell within 0.6 s to the fully dark-adapted absolute threshold. Thresholds of large (1.3 deg) tests were proportional to I (Weber law) and extinction thresholds, to root I. Conclusions: rod thresholds are elevated by photon-driven noise from dim fields that disappears at field extinction; large spot thresholds are additionally elevated by neural light adaptation proportional to root I. At night, recovery from dimly lit fields is fast, not slow. (C) 2016 Optical Society of America