Computer vision syndrome in presbyopia and beginning presbyopia: effects of spectacle lens type

Abstract

Purpose: This office field study investigated the effects of different types of spectacle lenses habitually worn by computer users with presbyopia and in the beginning stages of presbyopia. Computer vision syndrome was assessed through reported complaints and ergonomic conditions. Methods: A questionnaire regarding the type of habitually worn near-vision lenses at the workplace, visual conditions and the levels of different types of complaints was administered to 175 participants aged 35 years and older (mean ± SD: 52.0 ± 6.7 years). Statistical factor analysis identified five specific aspects of the complaints. Workplace conditions were analysed based on photographs taken in typical working conditions. Results: In the subgroup of 25 users between the ages of 36 and 57 years (mean 44 ± 5 years), who wore distance-vision lenses and performed more demanding occupational tasks, the reported extents of 'ocular strain', 'musculoskeletal strain' and 'headache' increased with the daily duration of computer work and explained up to 44 per cent of the variance (r s = 0.66). In the other subgroups, this effect was smaller, while in the complete sample (n = 175), this correlation was approximately rs = 0.2. The subgroup of 85 general-purpose progressive lens users (mean age 54 years) adopted head inclinations that were approximately seven degrees more elevated than those of the subgroups with single vision lenses. Conclusions: The present questionnaire was able to assess the complaints of computer users depending on the type of spectacle lenses worn. A missing near-vision addition among participants in the early stages of presbyopia was identified as a risk factor for complaints among those with longer daily durations of demanding computer work.

Comparison of progressive addition lenses for general purpose and for computer vision: an office field study

“…Participants may have used a 2.3 degrees higher head inclination with general purpose PALs (15.4 ± 5.2 degrees, eye‐ear line relative to horizontal) compared to computer vision PALs (13.1 ± 5.1 degrees) to compensate for this difference (at least in part). Significantly higher head inclinations with general purpose PALs were also found in other studies in relation to single near vision lenses that also do not restrict head position: the effect was 4.6 degrees (16.3 ± 6.9 versus 11.7 ± 5.1 degrees) (Weidling and Jaschinski, unpublished data) and 6.8 degrees (17.4 ± 9.2 versus 10.6 ± 9.4 degrees), respectively. Ergonomic studies report a favourable head inclination in the range of eight to 15 degrees (eye‐ear line relative to the horizontal) to avoid musculoskeletal strain.…”

“…The present sample comprised 23 users of general purpose PALs who had reported a relatively higher level of ocular and musculoskeletal strain in a preceding study one year earlier . At the start of the present study, they showed an average level of complaints, which can be explained by the typical effect of regression to the mean .…”

“…The participants were 23 PAL‐wearers (13 women, mean and standard deviation of age was 55 ± 4, range: 46 to 61 years). These participants were recruited from the sample in a previous field study of 175 computer users aged 35 to 63 years, where the mean questionnaire ratings were 1.49 ± 0.56 for ocular strain and 2.19 ± 1.29 for musculoskeletal strain. From these subjects, we recruited 23 participants based on two criteria.…”

The vertical monitor position for presbyopic computer users with progressive lenses: how to reach clear vision and comfortable head posture

“…In this way, the participants became acquainted with the procedure; even if single untypical postures may have been measured, these data will little affect the average of a series per day. The present method has been proven as useful in our previous studies because we found reliable individual changes in workplace postures after an office intervention (Meinert, König, and Jaschinski 2013) and a significantly higher head inclination by 2 -78 in users of generalpurpose progressive lenses (Jaschinski et al 2015a(Jaschinski et al , 2015b. The present results on head inclination in Figure 8 based on intra-individual comparisons further confirm this procedure.…”

“…Thus, for clear near vision, spectacle lenses are required. Spectacles with general-purpose progressive lenses are most frequently used (Jaschinski et al 2015a) due to their advantage of a gradual vertical change in near vision addition across the lens. This allows for clear vision at any viewing distance from far (e.g.…”