title: Depth of focus: clinical manifestation.
abstract: OBJECTIVE
  To assess depth of focus on the basis of measurements of the point spread function, which involve Stiles and Crawford phenomenon.
  
  
  METHODS
  Department of Ophthalmology of National Academy of Postgraduate Education.
  
  
  METHODS
  Gullstrand's schematic eye parameters and data of subjective measurement of size of diffusion circles were used for calculation of depth of focus. Data of 1171 eyes with visual acuity 1.0-2.0 were included in the study.
  
  
  RESULTS
  Under condition of visual acuity 1.5 data of the depth of focus were 0.38 D, 0.64 D, and 1.92 D for pupil diameter 5.0 mm, 3.0 mm, and 1.0 mm, respectively. Visual acuity 1.0 is characterized by larger value and visual acuity 2.0 by lesser value of the depth of focus.
  
  
  CONCLUSIONS
  Depth of focus and normal levels of visual acuity have a close relation: the higher the visual acuity, the smaller the depth of focus.
authors.affiliation: Department of Ophthalmology, National Medical Academy of Postgraduate Education, Kiev, Ukraine. nms@micro.kiev.ua
authors.forename: N M
authors.initials: NM
authors.lastname: Sergienko
authors.forename: N N
authors.initials: NN
authors.lastname: Tutchenko
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D006801:Humans; D011680:Pupil / Q000502:physiology*; D012029:Refraction, Ocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology*