Acta Scientific Ophthalmology (ISSN: 2582-3191)

Research Article Volume 5 Issue 1

Subjective Refractions Determined by Dyop® and Snellen Chart as Optotypes

Isiaka Sanni Oluwasegun*

Optometry and Vision Therapy, Albasar International Foundation, Makkah Specialist Hospital Bauchi, Nigeria

*Corresponding Author: Isiaka Sanni Oluwasegun, Optometry and Vision Therapy, Albasar International Foundation, Makkah Specialist Hospital Bauchi, Nigeria.

Received: November 23, 2021; Published: December 21, 2021


Purpose: Compare subjective refractive error and visual acuity measurement by Dyop® acuity chart and Snellen chart.

Methods: Forty subjects aged 24.48 ± 2.01 years with visual acuity better than 6/12 were recruited at University of Benin Optometry Clinic. Refractive error and corrected visual acuity were measured by subjective refraction method with Dyop® acuity chart and Snellen chart. The assessment sequence between the two acuity charts formats was alternated for every other patients to reduce potential refractionist bias. The duration of measurements was compared. Thibo’s notation was used to represent the refractive error findings to enhance easy analysis.

Results: There was no significant difference in terms of spherical equivalent (M), component J0 and J45 measured by Dyop® acuity chart and Snellen chart (even with age and gender consideration) for the subjective refractive error assessments but there was disparity in the mean acuity of about 0.25 diopters with Dyop (1.17 ± 0.14 decimal units) and Snellen chart (1.60 ± 0.21 decimal units). The subjective refraction measurement with Dyop (339 ± 122 seconds) took half the duration for Snellen’s (680 ± 281 seconds).

Conclusions: Subjective refractive error measurements by a Dyop® was comparable with Snellen chart. Dyop® subjective refractive error assessment was twice as efficient, with a narrower variance in visual acuity measurements, compared to the subjective refraction done with Snellen charts as optotype.


Keywords: Dyop®; Snellen Chart; Subjective Refraction; Visual Acuity


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Citation: Isiaka Sanni Oluwasegun. “Subjective Refractions Determined by Dyop® and Snellen Chart as Optotypes". Acta Scientific Ophthalmology 5.1 (2022): 43-45.


Copyright: © 2022 Isiaka Sanni Oluwasegun. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Acceptance rate35%
Acceptance to publication20-30 days
ISI- IF1.042
JCR- IF0.24

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