title: [Accommodation to monochromatic targets in people with different color vision statuses].
abstract: OBJECTIVE
  To compare the accommodation response (AR) to monochromatic targets in subjects with different color vision statuses, and to investigate the role of color vision in the control of accommodation and emmetropization.
  
  
  METHODS
  It was a case-control study. Accommodation was measured with a dynamic infrared optometer while subjects [17 protans, 47 deutans, and 23 normals; mean age: (20.0 ± 4.4) years] viewed a (1) red on black or (2) green on black vertical square-wave gratings of iso-luminance (3 cycles/deg; 0.9 contrast) in a Badal optic system. The grating stepped 1.00 D towards the eye from an initial position of 0 D until 5.00 D.
  
  
  RESULTS
  With red-black targets, the AR in the protans (AR = 1.98 D) was worse than that in the normals (AR = 2.55 D) when the accommodation stimulus (AS) was 4.00 D (LSD, P = 0.031). The AR in the deutans were worse than that in the normals when the AS was 3.00, 4.00, and 5.00 D (3.00 D: 1.23 D vs. 1.69 D, P = 0.002; 4.00 D: 1.89 D vs. 2.55 D, P = 0.002; 5.00 D: 2.40 D vs. 3.17 D, P = 0.003). With green-black targets, the AR in the protans were worse than that in the normals when the AS was 3.00 and 4.00 D (3.00 D: 1.13 D vs. 1.61 D, P = 0.004; 4.00 D: 1.80 D vs. 2.34 D, P = 0.021). In the deutans, the AR was worse with stimuli of 3.00, 4.00, and 5.00 D (3.00 D: 1.21 D vs. 1.61 D, P = 0.003; 4.00 D: 1.65 D vs. 2.34 D, P < 0.001; 5.00 D: 2.36 D vs. 2.93 D, P = 0.007). No significant differences between the protans and deutans were found for all the stimulus conditions. In the protans, accommodation to red-black targets was better than that to green-black targets when the stimulus was 2.00, 3.00, and 5.00 D (2.00 D: t = -2.81, P = 0.013; 3.00 D: t = -4.55, P < 0.001; 5.00 D: t = -3.15, P = 0.006). In the deutans, accommodation to red-black targets was better than that to green-black targets when the stimulus was 4.00 D (t = -2.19, P = 0.034). In the normals, accommodation to red-black targets were better than that to green-black targets when the stimulus was 2.00, 4.00, and 5.00 D (2.00 D: t = -2.57, P = 0.017; 4.00 D, t = -2.67, P = 0.014; 5.00 D: t = -2.15, P = 0.043).
  
  
  CONCLUSIONS
  Individuals with a color vision deficiency tend to have a larger accommodative lag than normals. Red targets tend to induce better accommodation response than green ones. Color vision may play a role in the control of accommodation and emmetropization.
authors: Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Myopia Key Lab of Health Ministry, Shanghai 200031, China.
authors: Yishan
authors: Y
authors: Qian
authors: Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Myopia Key Lab of Health Ministry, Shanghai 200031, China.
authors: Jia
authors: J
authors: Huang
authors: Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Myopia Key Lab of Health Ministry, Shanghai 200031, China. Email: churenyuan@hotmail.com.
authors: Renyuan
authors: R
authors: Chu
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D016022:Case-Control Studies; D055253:Color Vision; D003117:Color Vision Defects / Q000503:physiopathology*; D006801:Humans; D009907:Optometry / Q000295:instrumentation; D014785:Vision, Ocular / Q000502:physiology*