Occupational Visual Strain and Associated Ergonomic Risk Factors Among Watchmakers: A Cross-Sectional Study of Binocular Vision, Ocular Pain and Intraocular Pressure

Background: Watch repairing involves prolonged near-vision activity, monocular loupe use, sustained convergence, awkward postures, and repetitive fine motor movements, potentially contributing to ocular strain. The ocular and ergonomic impact of such occupations has not yet been documented. Objective: To study the ocular stress profile along with ergonomics risk factors among male watchmakers from Kolkata, India. Methods: This comparative cross-sectional study included 140 men aged 40–50 years, comprising 70 watchmakers with over 15 years of occupational exposure and 70 controls. Visual pain was assessed using a visual analogue scale (VAS), near point of convergence (NPC) and accommodation using the RAF rule, fusional vergence using a prism bar, ocular movements using a synoptophore, intraocular pressure (IOP) using non-contact tonometry, and visual acuity using a Snellen chart. Fundus photography and ergonomic assessments were also performed. Data were analysed using independent-samples t-tests (SPSS version 26; p<0.05). Results: Watchmakers exhibited significantly greater visual pain (7.29±0.58 cm vs. 3.81±0.30 cm; p<0.001) and receded NPC (16.57±1.51 cm vs. 7.86±1.35 cm; p<0.001), both remaining significant after Holm correction. Adduction was reduced (p=0.010), whereas IOP was higher in both eyes (p=0.044). Visual acuity and anthropometric differences were statistically insignificant. Major ergonomic concerns included inadequate rest periods, monocular loupe use, postural strain, and hand discomfort. Conclusion: Prolonged monocular near work by watchmakers can lead to convergence insufficiency-like symptoms, increased eye pain, and increased intraocular pressure. It is necessary for ergonomic measures such as using bi-ocular devices and proper work rest cycles and eye screenings to be taken.