ABSTRACT Background: Reaction time (RT) is utilized in everyday life in various populations for example in athletic training, geriatrics to prevent risk of fall, everyday activities like driving etc. At present, we devote a considerable amount of time to using digital devices for both work and recreation; therefore, it is essential to understand the positive and negative effects of them on the body. Materials & Methodology: 44 participants satisfying the inclusion criteria were exposed to 30 minutes of short wavelength blue light via short movie played on a laptop screen in a dark room. The reaction time and working memory was assessed pre and post 30 minute of exposure to blue light using computerized tests: Psychomotor vigilance test , Auditory reaction time test and Deary – Liewald task (DLT) for measuring visual, auditory and choice reaction time respectively and N-back test for measuring working memory. Results: Simple DLT (p value: 0.0459), choice DLT (p value: 0.00057) and N-back test (p value: 0.0153). P value of other tests were insignificant. Discussion: Results show significant improvements in reaction times and working memory accuracy after a 30-minute exposure. These enhancements are linked to heightened alertness and increased neural activation in prefrontal brain regions. However, visual and auditory reaction times remain unchanged. Further investigation is needed to understand persistence of these effects, highlighting blue light's promising role in potential cognitive enhancement and physiotherapeutic interventions. Conclusion: The results suggest that short duration blue light exposure during the day affects choice reaction time and working memory positively. Keywords: blue light, reaction time, screen time, working memory