title: Effects of flickering light on refraction and changes in eye axial length of C57BL/6 mice.
abstract: OBJECTIVE
  To investigate the effectiveness and feasibility of inducing myopia in mice by flickering-light (FL) stimulation.
  
  
  METHODS
  Forty-five 28-day-old C57BL/6 (B6) mice were randomly assigned to three groups: control group, FL stimulation group and form deprivation (FD) group. Mice in the control group were raised under 250 lux illumination from 8:00 a.m. to 8:00 p.m. Mice in the FL group were raised under illumination with a duty cycle of 50% at a flash rate of 2 Hz from 8:00 a.m. to 8:00 p.m. for 6 weeks. Mice in the FD group were raised under the same conditions as the control group; the right eyes of the mice were covered with semitransparent hemispherical plastic shells serving as eye diffusers. The refractive state and axial length (AL) of the right eyes were measured by eccentric infrared photorefraction and A-scan ultrasonography, respectively, before treatment and after 2, 4, 6 or 8 weeks' treatment.
  
  
  RESULTS
  After 6 weeks' exposure to FL, the refraction became more myopic compared with the control group as indicated by longer AL compared with the control group (p < 0.05); the FD eyes were more myopic than the FL eyes (p < 0.05). However, some mice lost their eye diffusers, and lens opacities were found.
  
  
  CONCLUSIONS
  Myopia can be induced by FL in B6 mice. The myopic shift induced by FL is less than that induced by FD, but FL causes fewer side effects, and is safery and easier to manipulate.
authors.affiliation: Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yu
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Jingsheng
authors.initials: J
authors.lastname: Tuo
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D000818:Animals; D058452:Axial Length, Eye / Q000000981:diagnostic imaging / Q000528:radiation effects*; D008027:Light / Q000009:adverse effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D009216:Myopia / Q000209:etiology*; D011833:Radiation Injuries, Experimental / Q000209:etiology*; D012029:Refraction, Ocular / Q000528:radiation effects*; D012683:Sensory Deprivation; D014463:Ultrasonography