IMPACT OF SMARTPHONE USE ON INTRAOCULAR PRESSURE: A COMPARATIVE STUDY OF DARK AND BRIGHT ROOM CONDITIONS IN HEALTHY YOUNG ADULTS: A CROSS-SECTIONAL STUDY

Abstract

Background: Intraocular pressure (IOP) is a critical determinant in the development and progression of glaucoma. Emerging evidence suggests that prolonged smartphone use, particularly involving sustained near-vision tasks, may induce transient elevations in IOP. However, the influence of ambient lighting conditions during smartphone use on IOP changes remains insufficiently explored, especially among healthy young adults who represent a high smartphone-using population.

Objective: To assess the effect of smartphone use on intraocular pressure under bright and dark room lighting conditions in healthy young adults.

Methods: A comparative cross-sectional study was conducted involving 154 healthy participants aged 15–30 years. Baseline IOP was measured using a non-contact air puff tonometer under standardized bright (300 lux) and dark (100 lux) room conditions. Participants then performed a continuous smartphone reading task for 15 minutes, after which IOP was re-measured in the same lighting environment. Each participant underwent assessments in both lighting conditions with a washout interval. Data were analyzed using SPSS version 27. Paired t-tests were applied to compare pre- and post-reading IOP within each lighting condition, while comparative analysis between bright and dark room post-reading IOP values was performed. Statistical significance was set at p < 0.05.

Results: A statistically significant increase in IOP was observed following smartphone use in both lighting conditions (p < 0.001). In the bright room, mean IOP increased from 14.76 ± 2.54 mmHg before reading to 16.78 ± 2.47 mmHg after reading. In the dark room, mean IOP rose from 15.72 ± 2.66 mmHg to 18.92 ± 2.51 mmHg following smartphone use. The post-reading IOP was significantly higher in the dark room compared to the bright room, indicating a greater magnitude of IOP elevation under low-light conditions.

Conclusion: Smartphone use resulted in a significant short-term increase in intraocular pressure in healthy young adults, with dark room conditions producing a more pronounced effect than bright environments. These findings highlight ambient lighting as an important modifiable factor during smartphone use and emphasize the need for preventive strategies and further research on long-term ocular health implications, particularly for individuals at risk of glaucoma.