Assessment of Prevalence of Dry Eye Disease amongst Adults with Screen Exposure of More than Six Hours at the Workplace

Background: Dry eye disease (DED) is a multifactorial disorder of the ocular surface characterised by loss of tear film homeostasis.1 Prolonged, uninterrupted near work on digital displays is one of the most consistently reported modifiable risk factors for DED, acting through a reduced and incomplete blink pattern, increased tear evaporation and tear film instability.15,16,22 Working adults whose screen exposure is occupational rather than recreational represent a large but comparatively under-characterised group in the Indian setting. The aim is to assess the prevalence, pattern and severity of dry eye disease among adults aged 20 to 50 years with occupational screen exposure exceeding six hours per day, using a self-administered symptom questionnaire and Schirmer's I test. Material and Methods: A cross-sectional, observational, descriptive-analytical study was conducted in the ophthalmology out-patient department of a tertiary eye care hospital in Maharashtra. Two hundred adults aged 20 to 50 years with an average occupational screen time of more than six hours per day for at least the preceding three to six months were enrolled by consecutive sampling after written informed consent. Participants with pre-existing ocular surface disease, contact lens wear, recent ocular surgery, systemic disease or medication known to reduce tear secretion, and lid or adnexal abnormalities were excluded. Each participant completed a ten-item symptom questionnaire, from which dry eye was graded as normal, mild, moderate or severe. Screen time was stratified as 6–8 hours, 8–10 hours and more than 10 hours per day. Schirmer's I test was performed and graded according to the Dry Eye WorkShop (DEWS) criteria as more than 15 mm (normal), 10–15 mm (mild), 5–10 mm (moderate) and less than 5 mm (severe). Results: Dry eye disease was identified in 88 of 200 participants, giving a prevalence of 44%. Of these, mild dry eye was seen in 38 participants (19%), moderate in 20 (10%) and severe in 30 (15%); 112 participants (56%) were graded as normal. Across the three exposure bands, dry eye of any severity was present in 53.73% (36 of 67) of those using screens for 6 to 8 hours daily, 33.33% (28 of 84) of those using them for 8 to 10 hours and 48.98% (24 of 49) of those exposed for more than 10 hours. Severe dry eye, however, was concentrated in the most heavily exposed group, affecting 26.53% of those using screens for more than 10 hours daily as against 11.94% and 10.71% in the two lower bands, and the association between exposure band and severity grade was statistically significant (χ² = 14.63, df = 6, p = 0.023). Mean Schirmer's I values declined progressively across symptom grades, from approximately 16–18 mm in the normal group to approximately 4–6 mm in the severe group, and the proportion of participants with an abnormal Schirmer value of less than 10 mm rose from 7.7% in the normal group to 38.3%, 76.1% and 92.4% in the mild, moderate and severe groups respectively. Conclusion: Nearly one in two adults with more than six hours of daily occupational screen exposure had symptomatic dry eye disease. Overall prevalence did not rise linearly with exposure band, but severe disease was significantly more frequent among those exposed for more than ten hours daily, indicating that very prolonged exposure acts chiefly by aggravating severity. Symptom grading showed good concordance with aqueous tear deficiency on Schirmer's testing, supporting the use of a brief questionnaire as a practical screening instrument in this population. Workplace ocular health programmes incorporating scheduled screen breaks, blink awareness and ergonomic correction are warranted.

Keywords: Dry eye disease, digital eye strain, computer vision syndrome, occupational screen time, Schirmer's test, tear film, ocular surface.