Related Experiment Video
Updated: Jul 11, 2026
Using an Automated Hirschberg Test App to Evaluate Ocular Alignment
Published on: March 24, 2020
Accuracy of the Nidek ARK-900 objective refractor in comparison with retinoscopy in children ages 3 to 18 years
M G Wood1, M L Mazow, T C Prager
1Department of Ophthalmology and Visual Science, University of Texas Health Science Center, Houston, USA.
Purpose:
To compare the increased speed and accuracy of the Nidek ARK-900 objective refractor with standard retinoscopy.
Methods:
In a prospective study, 100 children aged 3 to 18 years were refracted after cycloplegia. Visual acuity measurements were determined in randomized fashion with the Nidek objective refractor, by retinoscopy, and by subjective refraction. One eye from each patient was included in the study.
Results:
Ninety-six percent of the children read the 20/30 line perfectly with the result from the objective refractor compared to 88% with retinoscopy. The mean +/- SD visual acuity value obtained with the objective refractor was 20/24 +/- 4.75 and with retinoscopy was 20/27 +/- 6.8, a significant difference (paired t value = 4.81, P < .001).
Conclusion:
The Nidek ARK-900, representing the third generation of objective refractors, is comparable or superior to retinoscopy in accuracy in children, can be easily run by an ophthalmic technician, and therefore eliminates the physician's examination time required for retinoscopy.
