title: [Comparison study on subjective and objective measurements of the accommodative convergence to accommodation ratio].
abstract: OBJECTIVE
  To detect the accommodative convergence to accommodation (AC/A) ratios measured respectively by objective and subjective methods. The differences and its relative factors were explored.
  
  
  METHODS
  Forty young volunteers were measured by eye tracker to get the amount of convergence when fixating at the target at 100 cm, 50 cm, 33 cm and 25 cm and were measured by infrared auto-refractor to get corresponding accommodative responses. AC/A ratio based on these two measurements were compared with the calculated and the gradient AC/A ratio from Von Graefe tests.
  
  
  RESULTS
  Mean value of stimulated AC/A ratio measured by eye tracker was higher than the calculated and gradient AC/A ratio by Von Graefe method (P = 0.003, 0.001). There are statistic correlation (r = 0.871, P = 0.000) and difference (P = 0.000) between stimulated AC/A ratio and response AC/A ratios both measured by eye tracker, and the difference trends to be greater with the higher AC/A ratio.
  
  
  CONCLUSIONS
  The objective AC/A ratio is usually higher than the clinical subjective measurement because of more proximal effect. The response AC/A ratio measured objectively may reveal realistically the mutual effect and relationship between accommodation and convergence and it seems to be more credible to be the monitor parameter on progression of myopia in clinics.
authors.affiliation: The Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou 325027, China.
authors.forename: Jing-jing
authors.initials: JJ
authors.lastname: Xu
authors.forename: Dan
authors.initials: D
authors.lastname: Xu
authors.forename: Tao
authors.initials: T
authors.lastname: Huang
authors.forename: Jian
authors.initials: J
authors.lastname: Jiang
authors.forename: Fan
authors.initials: F
authors.lastname: Lü
mesh_terms: D000065:Accommodation, Ocular; D000328:Adult; D003290:Convergence, Ocular; D053483:Eye Movement Measurements; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult