Abstract

OBJECTIVES
The aim of this field-based longitudinal study was to investigate the effects of near-work on lacrimation and visual function, particularly refractive power.
METHODS
Our study tracked sixty five male workers for about three years by means of ophthalmologic examinations and questionnaires, to collect data including eye symptoms and subjective work environmental factors. Ophthalmic examinations included visual acuity, Shirmer I test, and autorefractometry. In the first year, the inclusion criteria were ages less than 40 years, no history of ophthalmic diseases, emmetropia(-1.0 RESULTS
Over a period of 32 months, spherical equivalents were decreased as much as 0.18D(diopter) for LE(left eye) and 0.18D for RE(right eye). Lacrimation by Shirmer's I test during 20 months were decreased as much as 6.57 mm/5min for LE, and 6.40 mm/5min for RE. Although more myopic-changed workers demonstrated young age(<30 years) and short work duration(<2 years), there was no significance to this correlation. Additionaly, subjective work environmental factors such as poor illumination, noise, uncomfortable air and daily use of VDT and/or TV were shown to have no significant effect. However, as for eye discomfort, which was reconstructed from several dry eye symptoms, the daily use of VDT and/or TV was a significant variable. According to a logistic regression analysis concerning the effects of refractive power, lacrimation, work duration, poor illumination, and daily use of VDT and/or TV on eye discomfort, only daily use of VDT and/or TV greater than 4 hours displayed OR of 10.5.
CONCLUSIONS
Myopic changes due to near work were not observed, however lacrimal function was changed in workers. These results suggest that we should consider various factors such as lacrimation, tear film and refraction as well as visual acuity in order to establish an eye care program among near-work performing employees.

• Keywords: Quality control;Workplace;Lacrimation;Visual acuity