An increase in popularity of the use of handheld electronics is resulting in changes in the postural and behavioral patterns of device users, as well as significant differences between presbyopes and non-presbyopes and between genders.
An analysis of features that possibly affect viewing distances when using smartphones by individuals of different age groups in different postures found significant differences between presbyopes and non-presbyopes and between males and females, according to Laura Boccardo, professor, Institute for Research and Study in Optics and Optometry, Vinci, Italy, and School of Mathematical, Physical and Natural Sciences (Optics and Optometry), University of Florence, Florence, Italy.
As she explained, the phenomenal increase in popularity of the use of handheld electronics such as smartphones and tablets is resulting in changes in the postural and behavioral patterns of the device users as well as the resultant variety of viewing styles and body postures among smartphone users.
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While younger individuals have been widely using smartphones for years, recently, she pointed out, “there has been significant growth in tech adoption also among the older generation, and the age gap in smartphone ownership has been closing since 2015.”
Regarding presbyopia, the decreased amplitude of accommodation with age results in different visual problems when using smartphones.
Because of this, she conducted a cross-sectional observational study1 both to measure habitual viewing distances with smartphones among individuals of different ages, i.e., those under 39 years and presbyopes over 40 years, and identify the factors that affect the viewing distance.
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Viewing distance study
She evaluated gender, reading position, forearm length, ametropia, correction modality, and near vision quality as potential factors affecting the viewing distances used with smartphones among 233 study participants (129 females, 104 males).
The individuals ranged in age from 16 to 90 years and they were divided by their visual status, presbyopic (n=102; range, 42 to 90 years) and non-presbyopic (n=131; range, 16 to 39 years).
All participants read a text message on their own smartphone while sitting and standing.
The overall viewing distances of all participants were 36.1 ± 7.2 cm while sitting and 37.4 ± 6.8 cm while standing, a difference that reached significance (p < 0.05) and 36.8 ± 6.6 cm overall.
When broken down by visual status, the average viewing distance was 35.0 ± 6.4 cm among non-presbyopes and 39.0 ± 6.1 cm among presbyopes, which also reached significance (p < 0.05).
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Among females, the average viewing distance was 34.7 ± 6.2 cm and 38.2 ± 6.3 cm among the males, also a significant difference (p < 0.001).
The takeaway points were that differences between males and females were seen because of the different average body sizes of the genders, the average viewing distance in presbyopes was about the same as the typical near reading distance (40 cm), and the accommodative demand among non-presbyopes using a smartphone was slightly greater compared with presbyopes.
Boccardo also noted that there was high variability in both age groups and no significant correlations seen with the other factors that were assessed.
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1. Boccardo L. Viewing distance of smartphones in presbyopic and non-presbyopic age. J Optom 2021;14:120-6; DOI: 10.1016/j.optom.2020.08.001