Recovery of spatial vision during dark adaptation in normal subjects

• Published in: Ophthalmic & physiological optics Vol. 17; no. 6; pp. 509 - 515
• Main Authors: MARGRAIN, T. H, THOMSON, W. D
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Blackwell 01.11.1997
• Subjects: Biological and medical sciences; Dark Adaptation - physiology; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Humans; Vertebrates: nervous system and sense organs; Vision Tests - instrumentation; Vision Tests - methods; Vision, Ocular - physiology; Human; Eye; Visual system; Vision; Physiology; Obscurity; Recovery; Spatial representation; Adaptation
• DOI: 10.1111/j.1475-1313.1997.tb00090.x
• ISSN: 0275-5408

We show, how sensitivity to sinusoidally-modulated gratings changes throughout the course of dark adaptation. The luminance required to resolve the bars of a variety of sinusoidal gratings of (0.6-14 c.p.d.) presented in the parafovea, was determined for 30 min following a full bleach. Data obtained for low and intermediate spatial frequencies (0.6 and 3.5 c.p.d.) was qualitatively similar to the classical dark adaptation function, showing discrete cone and rod phases. Threshold to a 14 c.p.d. grating fell initially, then after approximately 10 min, rose by between 0.40 and 1.17 log units. This effect was not apparent for the 8.3 c.p.d. grating, despite the fact that both spatial frequencies must have been detected by cones. The phenomenon has been attributed to rod-suppression of cone-mediated vision.