title: Effect of Blue Light-Reducing Eye Glasses on Critical Flicker Frequency.
abstract: OBJECTIVE
  This study aims to evaluate the effect of blocking short-wavelength light on critical flicker frequency (CFF).
  
  
  METHODS
  This study is a prospective clinical study.
  
  
  METHODS
  Thirty-three participants (17 men and 16 women; age range, 28-39 years) were divided into 3 groups. Each group wore 1 of 3 types of lenses while performing an intensive computer task for 2 hours. To evaluate the effect of blocking short-wavelength light before and after the task, we measured the CFF and evaluated subjective questionnaires. We used the analysis of variance test to examine whether the type of lenses tested affected any of the visual fatigue-related parameters.
  
  
  RESULTS
  The type of lens worn significantly affected the CFF; however, answers to the subjective questionnaires did not differ significantly between the groups. Two of the 13 question items showed a statistical difference between lens transparency and increase in the CFF (lens 3 > lens 2 > lens 1).
  
  
  CONCLUSIONS
  The higher the blocking effect of the lens, the lower the reduction in the CFF, suggesting that blocking short-wavelength light can reduce eye fatigue.
authors.affiliation: From the *Minamiaoyama Eye Clinic; and †Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ide
authors.forename: Ikuko
authors.initials: I
authors.lastname: Toda
authors.forename: Emiko
authors.initials: E
authors.lastname: Miki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tsubota
mesh_terms: D000328:Adult; D001248:Asthenopia / Q000209:etiology / Q000517:prevention & control*; D016288:Computer Terminals; D058447:Eye Pain / Q000209:etiology / Q000517:prevention & control*; D005139:Eyeglasses; D005260:Female; D005425:Flicker Fusion / Q000502:physiology*; D006801:Humans; D008027:Light / Q000009:adverse effects*; D008297:Male; D011446:Prospective Studies; D014792:Visual Acuity