Purchase this article with an account.
Mark Rosenfield, Min Lan, Longqian Liu; CELL PHONE VIEWING DISTANCE AND AGE IN A CHINESE POPULATION. Invest. Ophthalmol. Vis. Sci. 2017;58(8):5420.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
A previous study from our laboratory demonstrated that the average viewing distance adopted when viewing a smartphone in American subjects between 18 and 39 years of age was 36.2cm (1). This is closer than the reading distance typically adopted when viewing printed materials. Given the very high prevalence of myopia in China (approaching 90% in some areas), the aim of this investigation was to examine whether the mean cell phone viewing distance in a Chinese population was closer than that found in the U.S.A., and to examine the effect of age on this parameter.
207 visually-normal Chinese subjects were tested. They were instructed to view a text message on their cell phone, and to hold the device as if they were about to read the text. The distance from the phone to the spectacle plane was measured using a rigid tape measure. The subjects ranged in age from 16 to 74 years, with a mean of 34 years (SEM = 0.76yrs).
The mean viewing distance was 33.95cm (SEM = 0.41cm, range 19.0 - 51.3cm). A weak, but significant positive correlation (r = 0.24, p < 0.0001) was found between age and viewing distance. No significant difference in viewing distance was observed when comparing spectacle (N=84) versus non-spectacle (N=123) wearers (p=0.91).
These findings confirm the previous results that modern cell phones are held at closer viewing distances than printed materials. Further, the mean viewing distance adopted in a Chinese population was over 2cm closer than that found in American subjects. Only a small increase in viewing distance was found with age, presumably due to the onset of clinical presbyopia. This increased demand on both ocular accommodation and vergence, compared with hardcopy materials, could be responsible for symptoms of digital eye strain commonly experienced in many individuals.1. Bababekova et al., Optom Vis Sci 2011; 88: 795-7.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
This PDF is available to Subscribers Only