Laura Boccardo1. 1. Institute for Research an Study in Optics and Optometry (IRSOO), Vinci, Italy; School of Mathematical, Physical and Natural Sciences (Optics and Optometry), University of Florence (UNIFI), Italy. Electronic address: laura.boccardo@unifi.it.
Abstract
PURPOSE: The aim of this cross-sectional observational study was to measure habitual viewing distance with smartphones in individuals of different ages, and to identify factors influencing viewing distance. MATERIAL: Gender, reading position, forearm length, ametropia, correction modality, and near vision quality were investigated as factors affecting viewing distance. Participants were asked to read a typical text message on their own smartphone, while sitting and standing. A total of 233 subjects (129 females and 104 males), aged from 16 to 90 years old, were included and divided in two groups: 131 non-presbyopes (median 21.1, range 16 - 39), and 102 presbyopes (median 54.5, range 42 - 90). RESULTS: Mean viewing distance was 36.1 ± 7.2 cm while sitting, and 37.4 ± 6.8 cm while standing (P < 0.05), and 36.8 +/- 6.6 cm overall. The average viewing distance was 35.0 ± 6.4 cm in non-presbyopes, and 39.0 ± 6.1 cm in presbyopes (P < 0.05). The average viewing distance was 34.7 ± 6.2 cm in females, and 38.2 ± 6.3 cm in males (P < 0.001). CONCLUSIONS: Significant differences between males and females were observed, due to the different average body size between the two gender groups. Average viewing distance with smartphones in presbyopes matched approximately to the typical near reading distance of 40 cm. In the non-presbyopic group, the accommodative demand when reading a smartphone was slightly higher than in the presbyopic group. High variability was observed in both age groups, without a statistically significant correlation with other assessed factors as reading position, ametropia, correction modality, and near vision quality.
PURPOSE: The aim of this cross-sectional observational study was to measure habitual viewing distance with smartphones in individuals of different ages, and to identify factors influencing viewing distance. MATERIAL: Gender, reading position, forearm length, ametropia, correction modality, and near vision quality were investigated as factors affecting viewing distance. Participants were asked to read a typical text message on their own smartphone, while sitting and standing. A total of 233 subjects (129 females and 104 males), aged from 16 to 90 years old, were included and divided in two groups: 131 non-presbyopes (median 21.1, range 16 - 39), and 102 presbyopes (median 54.5, range 42 - 90). RESULTS: Mean viewing distance was 36.1 ± 7.2 cm while sitting, and 37.4 ± 6.8 cm while standing (P < 0.05), and 36.8 +/- 6.6 cm overall. The average viewing distance was 35.0 ± 6.4 cm in non-presbyopes, and 39.0 ± 6.1 cm in presbyopes (P < 0.05). The average viewing distance was 34.7 ± 6.2 cm in females, and 38.2 ± 6.3 cm in males (P < 0.001). CONCLUSIONS: Significant differences between males and females were observed, due to the different average body size between the two gender groups. Average viewing distance with smartphones in presbyopes matched approximately to the typical near reading distance of 40 cm. In the non-presbyopic group, the accommodative demand when reading a smartphone was slightly higher than in the presbyopic group. High variability was observed in both age groups, without a statistically significant correlation with other assessed factors as reading position, ametropia, correction modality, and near vision quality.
Authors: Yi-Lang Chen; Kuan-Hsiang Chen; Yu-Cheng Cheng; Chien-Ching Chang Journal: Int J Environ Res Public Health Date: 2022-04-11 Impact factor: 4.614