COMPARATIVE EVALUATION OF OCULAR SURFACE CHANGES IN INDIVIDUALS WITH AND WITHOUT BLUE LIGHT EXPOSURE

Abstract

This study evaluates and compares corneal surface changes in individuals exposed to blue light and those with minimal exposure. A comparative cross-sectional study was conducted at Saveetha Medical College, Chennai, involving 60 participants divided into two groups: a blue light-exposed group (n=30) with daily screen exposure exceeding four hours and a non-exposed group (n=30) with screen exposure of less than 30 minutes per day. Comprehensive ocular examinations were performed, including visual acuity assessment, slit-lamp biomicroscopy, intraocular pressure (IOP) measurement, and corneal surface evaluation using Tear Break-Up Time (TBUT), Schirmer’s test, corneal staining, and corneal topography. Symptoms such as dryness, irritation, and fatigue were documented using the Ocular Surface Disease Index (OSDI) questionnaire.

Results showed significantly lower TBUT in the blue light-exposed group (5.72 ± 1.33 s) compared to the non-exposed group (11.76 ± 1.83 s, p<0.001), indicating tear film instability. Schirmer’s test values were also lower in the exposed group (12.04 ± 2.93 mm vs. 14.94 ± 2.68 mm, p=0.0002), while corneal staining scores were higher (p<0.001), suggesting increased epithelial damage. Slit-lamp bio microscopy findings revealed a higher prevalence of epithelial defects and conjunctival hyperemia in the exposed group, whereas the non-exposed group showed a greater proportion of normal corneas. OSDI scores indicated a significantly higher prevalence of dry eye symptoms in the exposed group (p<0.001). However, IOP measurements (p=0.200) and corneal topography showed no significant differences between groups.

The findings suggest that prolonged blue light exposure negatively impacts corneal surface integrity by reducing tear film stability and increasing epithelial stress. While IOP and corneal curvature remained unaffected, the increased prevalence of ocular discomfort highlights the need for preventive strategies such as blue light filters, artificial tears, and regulated screen time. Further longitudinal studies are necessary to assess the long-term effects of blue light exposure on ocular health.