Document Detail


U.S. Army sunglasses: issues and solutions.
MedLine Citation:
PMID:  8888832     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Some military aviators have reported difficulty discriminating the color of cockpit warning lights when wearing plastic sunglasses. This difficulty could be due to lenses that are too dark or are nonneutral and thus alter color vision. A study was performed to identify the origin of this problem, recommend solutions, and determine a sunglass transmittance that optimizes visual performance. METHODS: Five pairs of plastic sunglasses (-4 to +4 D) were ordered from each of seven military optical laboratories (70 lenses total). Each laboratory was instructed to dye the lenses neutral gray with 21 percent transmittance. Light transmittance and color distortion were evaluated across laboratory and lens power. Spatial and color vision were assessed through a range of sunglass transmittances. RESULTS: There was no systematic effect of lens power, but light transmittance and color distortion varied widely across laboratories (transmittance = 1 to 30 percent; p < 0.001). CONCLUSIONS: Because light transmittance and color distortion were related inversely, it was believed that both factors could be corrected by accurate verification of transmittance, but commercial transmittance meters proved to be inaccurate. The high transmittance of deep red and infrared light through plastic lens dyes is read as visible light by transmittance meters, making readings too high. A filter was identified that provides accurate readings when used with transmittance meters. A sunglass transmittance of 23 percent resulted in minimal decrease in visual performance relative to normal clinical test conditions.
Authors:
J C Rabin; R W Wiley; R R Levine; J P Wicks; A G Rivers
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of the American Optometric Association     Volume:  67     ISSN:  0003-0244     ISO Abbreviation:  J Am Optom Assoc     Publication Date:  1996 Apr 
Date Detail:
Created Date:  1996-12-04     Completed Date:  1996-12-04     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  7505575     Medline TA:  J Am Optom Assoc     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  215-22     Citation Subset:  IM    
Affiliation:
USAARL, Fort Rucker, AL, USA.
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MeSH Terms
Descriptor/Qualifier:
Analysis of Variance
Eyeglasses / standards*
Filtration
Humans
Military Personnel*
Optics and Photonics
Spectrophotometry
United States

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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