title: Effects of horizontal acceleration on human visual acuity and stereopsis.
abstract: The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (< and >0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration <0.1 g in the X- or Y-axis did not affect dynamic vision and stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR) and stereopsis declined significantly (mean from 40 s to 60.2 s of arc) when Gx > 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy.
authors.affiliation: Medical Education Center, Kaohsiung Armed Forced General Hospital, Kaohsiung City 802, Taiwan. csmcysh@csmu.edu.tw.
authors.forename: Chi-Ting
authors.initials: CT
authors.lastname: Horng
authors.affiliation: Institute of Biochemistry and Biotechnology, Chung Shang Medical University and Chung Shang Medical University Hospital, Taichung City 402, Taiwan. csmcysh@csmu.edu.tw.
authors.forename: Yih-Shou
authors.initials: YS
authors.lastname: Hsieh
authors.affiliation: Department of Ophthalmology, Taipei Buddhist Tzu Chi General Hospital, Taipei City 231, Taiwan. doc30845@yahoo.com.tw.
authors.forename: Ming-Ling
authors.initials: ML
authors.lastname: Tsai
authors.affiliation: Medical Affairs Bureau, Ministry of National Defense, Taipei City 104, Taiwan. weiching8277@gmail.com.
authors.forename: Wei-Kang
authors.initials: WK
authors.lastname: Chang
authors.affiliation: Medical Education Center, Kaohsiung Armed Forced General Hospital, Kaohsiung City 802, Taiwan. yingchuan@ms.szmc.edu.tw.
authors.forename: Tzu-Hung
authors.initials: TH
authors.lastname: Yang
authors.affiliation: Department of Ear-Nose-Throat, Kaohsiung Armed Forced General Hospital, Kaohsiung City 802, Taiwan. rebecca7255@yahoo.com.tw.
authors.forename: Chien-Han
authors.initials: CH
authors.lastname: Yauan
authors.affiliation: Medical Affairs Bureau, Ministry of National Defense, Taipei City 104, Taiwan. b00401122@ntu.edu.tw.
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei City 100, Taiwan. h56041@gmail.com.
authors.forename: Wu-Hsien
authors.initials: WH
authors.lastname: Kuo
authors.affiliation: Medical Affairs Bureau, Ministry of National Defense, Taipei City 104, Taiwan. westlife7833000@yahoo.com.tw.
authors.forename: Yi-Chang
authors.initials: YC
authors.lastname: Wu
mesh_terms: D000054:Acceleration; D000293:Adolescent; D000328:Adult; D003867:Depth Perception; D005260:Female; D006801:Humans; D008297:Male; D013624:Taiwan; D014792:Visual Acuity; D014796:Visual Perception; D055815:Young Adult