title: Incidence of myopia in high school students with and without red-green color vision deficiency.
abstract: OBJECTIVE
  To investigate the influence of color vision on myopia development by testing refraction error and axial length of the eye for high school students with and without color vision deficiency (CVD).
  
  
  METHODS
  A school-based cross-sectional, cluster sample study was conducted to test the color vision and refractive error of 16,539 high school students. Students were screened for CVD using a pseudoisochromatic plate. CVD was confirmed in students failing the test using a Farnsworth-Munsell 100-Hue Test which also served to classify the subtype (protan or deutan). Three classmates of each CVD subject, matched in five myopia risk factors, were chosen to form the normal color vision (CN) control group. Ophthalmic examinations were performed to determine refractive status and axial length.
  
  
  RESULTS
  Of the students, 309 were found to have red-green CVD and 927 were selected as the CN control group. The prevalence of myopia in the CVD group (45.6%) was significantly lower than that of the CN group (65.8%; P<0.001). The CVD group was also less myopic in refraction (P<0.001) than CN, and protan subjects had shorter axial lengths than those in the control group (P=0.007).
  
  
  CONCLUSIONS
  Color vision deficiencies appear to influence the development of myopia. The observed lower incidence of myopia in people with CVD may be linked to the reduced functionality of the L/M chromatic mechanism.
authors.affiliation: Department of Ophthalmology, Eye Ear Nose and Throat Hospital, Shanghai, People's Republic of China.
authors.forename: Yi-Shan
authors.initials: YS
authors.lastname: Qian
authors.forename: Ren-Yuan
authors.initials: RY
authors.lastname: Chu
authors.forename: Ji C
authors.initials: JC
authors.lastname: He
authors.forename: Xing-Huai
authors.initials: XH
authors.lastname: Sun
authors.forename: Xing-Tao
authors.initials: XT
authors.lastname: Zhou
authors.forename: Nai-Qing
authors.initials: NQ
authors.lastname: Zhao
authors.forename: Dan-Ning
authors.initials: DN
authors.lastname: Hu
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Hoffman
authors.forename: Jin-Hui
authors.initials: JH
authors.lastname: Dai
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Qu
authors.forename: Kristina E Yi-Hwa
authors.initials: KE
authors.lastname: Pao
mesh_terms: D000293:Adolescent; D002681:China / Q000453:epidemiology; D003119:Color Perception Tests; D003117:Color Vision Defects / Q000453:epidemiology* / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009216:Myopia / Q000453:epidemiology* / Q000503:physiopathology; D015995:Prevalence; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000453:epidemiology; D017678:Sex Distribution; D011795:Surveys and Questionnaires