Continuous recording of accommodation and pupil size using the Shin-Nippon SRW-5000 autorefractor.
A newly released commercial autorefractor, the Shin-Nippon SRW-5000 (Japan), has been found to be valid compared to subjective refraction and repeatable over a wide prescription range. Its binocular open field-of-view allows the accommodative state to be monitored while a natural environment is viewed. In conventional static mode, the device can take up to 45 readings in 1 min using digital image analysis of the reflected retinal image of a measurement ring. Continuous on-line analysis of the ring provides high (up to 60 Hz) temporal resolution of the refractive state to an accuracy of < 0.001 D. Pupil size can also be analysed to a resolution of < 0.001 mm. The measurement of accommodation and pupil size was relatively unaffected by eccentricity of viewing up to +/- 10 degrees and instrument focusing inaccuracies of +/- 5 mm. The resolution properties of the analysis are shown to be ideal for measurement of dynamic accommodation and pupil responses.
Neurosciences Research Institute, School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK. j.s.w.wolffsohn@aston.ac.uk
J S
JS
Wolffsohn
B
B
Gilmartin
E A
EA
Mallen
S
S
Tsujimura
D000065:Accommodation, Ocular / Q000502:physiology*; D006801:Humans; D009885:Ophthalmology / Q000295:instrumentation*; D011680:Pupil / Q000502:physiology*; D012030:Refractive Errors / Q000175:diagnosis; D015351:Vision Screening / Q000295:instrumentation* / Q000592:standards