Related Experiment Video
Updated: Aug 12, 2026
Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients
Published on: March 29, 2022
The effect of off-the-visual-axis retinoscopy on objective refractive measurement
David W Jackson1, Evelyn A Paysse, Kirk R Wilhelmus
1Cullen Eye Institue, Baylor College of Medicine, and Department of Ophthalmology, Texas Children's Hospital, Houston, 77030, USA.
Purpose:
To determine the effect of off-axis retinoscopy on objective refractive measurement.
Design:
Prospective experimental study.
Methods:
Eight volunteers underwent cycloplegic retinoscopy of their right eye on-the-visual-axis, and 5, 10, 15, and 20 degrees off-the-visual-axis in adduction. A single masked examiner performed all retinoscopy with random order of the patient and axis refracted.
Results:
The average spherical retinoscopic value at 0, 5,10,15, and 20 degrees of off-axis alignment was -0.40, -0.90, -1.00, -1.38, and -1.80 diopters, respectively. The average spherical equivalent retinoscopic value obtained for each of the above positions of eye alignment was -0.02, -0.59, -0.45, -0.64, and -0.98 diopters, respectively. The induced cylinder power increased by an average of 3% for each degree of off-axis retinoscopy, though the axis of the cylinder was not predictable.
Conclusion:
Objective refractive measurement by retinoscopy is significantly altered by off-the visual-axis retinoscopy. The induced error may be clinically important even with small degrees of eccentricity.
