The response of the accommodation system to digital and print images

Minette Devenier,Tuwani A Rasengane,Rekha Hansraj

doi:10.4102/aveh.v80i1.662

Minette Devenier, Tuwani A Rasengane + Show 1 more

Open Access

https://doi.org/10.4102/aveh.v80i1.662

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Abstract

Background: The transition from traditional print medium to a digital medium may affect the accommodative response (AR) because of the differences in the characteristics of the targets viewed.Aim: This study investigated how the accommodation system responded to targets displayed on a tablet computer compared to that on paper.Setting: The study was conducted amongst students at a university in South Africa.Methods: Using a quantitative, cross-sectional study the AR, amplitude of accommodation (AA), and accommodative facility (AF) were assessed with a target on an iPad and a paper-based one on a non-probability sample of 30 university students. Data was analysed using descriptive statistics and Bland Altman plots.Results: The median AR with a tablet was +0.25 dioptre (D) compared to +0.21 D with the paper-based target. This difference was neither statistically nor clinically significant. The median AA with a tablet computer target was 10.59 D and 9.85 D with a paper-based target. While this difference was statistically significant (p = 0.002), Bland Altman analysis revealed comparable measurements with both types of targets. Both Wilcoxon Signed Ranks Test (p = 0.462) and Bland Altman analysis found comparable medians for AF obtained with a target on paper (7.67 cycles per minute [cpm]) and a target on the tablet computer (7.17 cpm) to be comparable.Conclusion: The accuracy, strength and flexibility of accommodation were comparable for tablet computer and paper-based targets.

Highlights

Computer technology has evolved considerably, and rapidly, over the past decades with the most recent advance being the transition from desktops to laptops and to even smaller mobile devices, one of which is a tablet computer
Accommodation was assessed in terms of the accommodative response (AR), AA and accommodative facility (AF), using an iPad target and a paper target, as these are the parameters that are useful in assessing the accommodative system and are active during near work
Even though studies by Sorkin, Reich and Pizzimenti[26] and Penisten et al.[18] used an objective method that is dynamic retinoscopy, instead of the subjective method used in the current study, to assess the AR to targets on a video display terminal to printed texts, they reported a higher lag of accommodation to the digital target

Summary

Introduction

Computer technology has evolved considerably, and rapidly, over the past decades with the most recent advance being the transition from desktops to laptops and to even smaller mobile devices, one of which is a tablet computer. Results show that the use of tablet computers in tertiary education, has increased twice as much even in the course of a single year[5] with teaching and learning having become reliant on digital learning platforms. The popularity of these devices can be attributed to them being reasonably priced, environmentally friendly, and enabling an entire library to be carried in a backpack.[6]. On the flip side, computer-based tasks have been associated with computer vision syndrome (CVS), known as digital strain, which Rosenfield et al.[7] defined as ‘the combination of eye and visual problems associated with the use of computers’. The transition from traditional print medium to a digital medium may affect the accommodative response (AR) because of the differences in the characteristics of the targets viewed

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