Effect of Chemical Exposure on Colour Vision
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Abstract
Background: Occupational exposure to organic solvents and industrial chemicals may impair retinal or neuro-ophthalmic function, producing acquired colour vision defects that can remain undetected in workplace populations. Objective: This study aimed to evaluate the association between occupational chemical exposure and colour vision defects among industrial workers. Methods: A cross-sectional observational study was conducted at Pulcra Chemicals Pvt. Limited and Rudolf Chemicals Pakistan from July to November 2025. Eighty-two participants aged 20–60 years were included and divided equally into exposed and non-exposed groups. Participants with congenital colour blindness, ocular disease, systemic disease affecting vision, or medication use known to alter colour perception were excluded. Ishihara plates were used to screen for congenital red–green defects, and the Farnsworth D-15 test was used to assess acquired dyschromatopsia. Data were analyzed using SPSS, and associations were tested using chi-square and Fisher’s exact tests. Results: Abnormal colour vision was identified in 33 of 41 exposed workers (80.5%) compared with 4 of 41 non-exposed participants (9.8%). The association between exposure status and D-15 findings was statistically significant, χ² = 42.866, p < 0.001, with a large effect size. Tritan-type defects were the most frequent abnormalities among exposed workers. Conclusion: Occupational chemical exposure was strongly associated with acquired colour vision impairment, particularly blue–yellow defects. Routine colour vision screening and improved workplace safety measures are recommended
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References
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