Study on the regulation of contrast visual acuity based on special combat branch population

Objective To explore the change rules on visual acuity of special combat branch population who have normal one confirmed by physical examination under different backgrounds in different contrasts and to evaluate the important significance of contract visual acuity in whole-army physical examination.Methods From December 2012 to February 2013 vision compliance personnel 336 cases(672 eyes) of ×××××× troop of Jinan military region were enrolled in this study by using multifunctional electronic vision measuring instrument(MFVA100) in the dark room under a dark background,standard background,bright background in the contrast of 100%,25%,10%,5% the LogMAR vision were detected and grouped according to the contrast and background luminance.SPSS 19 statistical software was used for analysis of quantitative data of single factor variance,and correlation test among all groups.Results Along with the decline of contrast,three groups under different background luminance group vision decreased,under the low contrast visual acuity was significantly lower than the contrast group;among low contrast,general and bright group and high group contrast visual acuity had no significant differences;100% of background luminance contrast group was positirely and linearly correlated with groups of 25%,10%,5% in contrast visual acuity group were(P0.001).With the decrease of contrast,fluctuation of each visual acuity increased,when contrast was 5% vision fluctuation became the largest.Conclusion In a certain range of contrast,with enhanced vision visual background brightness also increased,while in contrast is low,the background brightness is increased to a certain degree,vision does not change significantly;Contrast visual acuity test has important value in the visual function examination for whole-army,and provides reference for detecting selection for special units and occupations.