Document Detail

Laser-induced chromatic adaptation.
MedLine Citation:
PMID:  3177590     Owner:  NLM     Status:  MEDLINE    
Detecting a target in a visually noisy back-ground depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels may act as a masking source by reducing the observer's ability to resolve differences in the visual scene. The experiment reported here specifically investigates the comparability of shuttered CW and Q-switched visible lasers to alter/degrade color discrimination. Visual evoked potentials (VEP's) were used to examine the short time course effects in monkeys of luminance-matched flashes from a 694 nm ruby Q-switched laser and 100 ms shuttered krypton CW laser (676, 568, and 531 nm lines). The test stimulus was a shifting pattern of alternating luminance-matched 510 and 550 nm green bars. With flashes equated to 4.8 log T-s, similar flash effect curves were seen, demonstrating 1.5-s changes in response magnitude. This level of flash did not extinguish the response to the stimulus. The flash effects curve was "W"-shaped, with an intermediate signal peak occurring at approximately 500 ms after the flash and whose level exceeded the baseline magnitude. The hypothesized mechanism for this result is an induced luminance imbalance caused by a transient shift in the peak color responsiveness of the visual system, which recovers with two different time constants. It is concluded that red and green colored laser flashes shift the color balance transiently in the visual system (yellow flashes to a lesser extent); thus, targets may change both hue and brightness after an observer receives colored flashes.(ABSTRACT TRUNCATED AT 250 WORDS)
E T Schmeisser
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  American journal of optometry and physiological optics     Volume:  65     ISSN:  0093-7002     ISO Abbreviation:  Am J Optom Physiol Opt     Publication Date:  1988 Aug 
Date Detail:
Created Date:  1988-11-01     Completed Date:  1988-11-01     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  0417614     Medline TA:  Am J Optom Physiol Opt     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  644-52     Citation Subset:  IM; S    
USAF School of Aerospace Medicine, Brooks Air Force Base, San Antonio, Texas.
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MeSH Terms
Adaptation, Ocular / radiation effects*
Color Perception / radiation effects*
Evoked Potentials, Visual / radiation effects
Macaca mulatta
Photic Stimulation / methods

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