title: Comparison of visual status of Iranian military and commercial drivers.
abstract: BACKGROUND
  There is no legal requirement for Iranian military truck drivers to undergo regular visual checkups as compared to commercial truck drivers.
  
  
  OBJECTIVE
  This study aimed to evaluate the impact of drivers' visual checkups by comparing the visual function of Iranian military and commercial truck drivers.
  
  
  METHODS
  In this comparative cross-sectional study, two hundred military and 200 commercial truck drivers were recruited and their Visual Acuity (VA), Visual Field (VF), color vision and Contrast Sensitivity (CS) were assessed and compared using the Snellen chart, confrontation screening method, D15 test and Pelli-Robson letter chart, respectively. A questionnaire regarding driving exposure and history of motor-vehicle crashes (MVCs) was also filled by drivers. Results were analyzed using an independent samples t-test, one-way ANOVA (assessing difference in number of MVCs across different age groups), chi-square test and Pearson correlation at statistical significance level of P < 0.05.
  
  
  RESULTS
  Mean age was 41.6 ± 9.2 for the military truck drivers and 43.4 ± 10.9 for commercial truck drivers (P > 0.05). No significant difference between military and commercial drivers was found in terms of driving experience, number of MVCs, binocular VA, frequency of color vision defects and CS scores. In contrast, the last ocular examination was significantly earlier in military drivers than commercial drivers (P < 0.001). In addition, 4% of military drivers did not meet the national standards to drive as opposed to 2% of commercial drivers. There was a significant but weak correlation between binocular VA and age (r = 0.175, P < 0.001). However, CS showed a significantly moderate correlation with age (r = -0.488, P < 0.001).
  
  
  CONCLUSIONS
  The absence of legal requirement for regular eye examination in military drivers caused the incompetent drivers to be missed in contrast to commercial drivers. The need for scientific revision of VA standard for Iranian drivers is also discussed. The CS measurement in visual checkups of older drivers deserves to be investigated more thoroughly.
authors.affiliation: Health Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ghasemi
authors.affiliation: Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia.
authors.forename: Seyed Hosein
authors.initials: SH
authors.lastname: Hoseini Yazdi
authors.affiliation: Department of Optometry, Paramedical Faculty, Mashhad University of Medical Sciences, Mashhad, IR Iran.
authors.forename: Javad
authors.initials: J
authors.lastname: Heravian
authors.affiliation: Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Jafarzadehpur
authors.affiliation: Trauma Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Rezaee
keywords: Color Vision; Contrast Sensitivity; Visual Acuity; Visual Fields