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. 2023 Apr 12;18(4):e0282947.
doi: 10.1371/journal.pone.0282947. eCollection 2023.

Viewing distance and character size in the use of smartphones across the lifespan

Laura Boccardo  1   2 , Massimo Gurioli  1 , Paolo Antonino Grasso  1
Affiliations

Viewing distance and character size in the use of smartphones across the lifespan

Laura Boccardo et al. PLoS One. .

Abstract

The use of smartphones has seen an extraordinary growth in recent years, thus the understanding of visual habits associated with the use of such devices across the lifespan is becoming important. In the present study we measured viewing distance and character size in a group of non-presbyopes (n = 157) and a group of presbyopes (n = 60) while participants read a simple text message on their smartphone. Results showed that non-presbyopes use shorter viewing distances as compared to presbyopes, a behavior causing a significantly higher accommodative demand. Presbyopes also use larger character sizes and this behavior is more evident whenever difficulties in near vision emerge in the Near Activity Visual Questionnaire (NAVQ, Italian version). Nevertheless, the two groups did not differ in the measurement of angular size subtended by the smallest detail of the letters. Overall, our data reveal that non-presbyopes and presbyopes have different visual habits when using a smartphone. These differences should be considered when determining the best near correction.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Experimental procedure.
Participants received a text message and were instructed to read it. Reading distance and character size were obtained.
Fig 2
Fig 2. Scatterplot depicting values of reading distance (A) and accommodative demand (B) for non-presbyopes and presbyopes.
Asterisks depicts average values while different colors represent different ages (*** = p < 0.001).
Fig 3
Fig 3. Correlations between reading distances obtained using tape measure and the use of a dedicated smartphone application.
Fig 4
Fig 4. Scatterplot depicting values of character size (A) and angular size (B) for non-presbyopes and presbyopes.
Asterisks depicts average values while different colors represent different ages (*** = p < 0.001).
See this image and copyright information in PMC

References

    1. Statista. Daily usage of smartphone in Italy in 2019. 2019. Available: https://www.statista.com/statistics/1084948/daily-usage-of-smartphone-in...
    1. Rosenfield M, Howarth PA, Sheedy JE, Crossland MD. Vision and IT displays: A whole new visual world. Ophthalmic and Physiological Optics. 2012. doi: 10.1111/j.1475-1313.2012.00936.x - DOI - PubMed
    1. Bababekova Y, Rosenfield M, Hue JE, Huang RR. Font size and viewing distance of handheld smart phones. Optom Vis Sci. 2011;88. doi: 10.1097/OPX.0b013e3182198792 - DOI - PubMed
    1. Boccardo L. Viewing distance of smartphones in presbyopic and non-presbyopic age. J Optom. 2021;14. doi: 10.1016/j.optom.2020.08.001 - DOI - PMC - PubMed
    1. Charman WN. The eye in focus: Accommodation and presbyopia. Clinical and Experimental Optometry. 2008. doi: 10.1111/j.1444-0938.2008.00256.x - DOI - PubMed

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