Abstract
Background: Smartphones, PC, tablets, and TV have become integral parts of our lives. The smartphone in particular is the lifeline of everyone, regardless of their age group. Overuse of smartphones is increasing, resulting in a great deal of physical and psychological effects. It is found to negatively impact health and increase the risk of stress, depression, and anxiety. In addition to this, sleep disorders, restlessness, and fatigue are also being reported which can lead to cognitive impairment. The reaction time (RT) is the interval between the application of a stimulus and the response. It is an indication of neural processing between a stimulus and the response which is expressed in milliseconds.

Aims and Objectives: The primary objective of this study was to estimate screen time, auditory and visual RTs, and the association between screen time and RT (visual reaction time [VRT] and auditory reaction time [ART]).

Materials and Methods: The present cross-sectional study was conducted on 232 1st year MBBS students in the age group of 18–23 years. Average screen time was noted from their respective gadgets. RT for the targeted stimulus, yellow light for the VRT and beep sound for the ART, was determined using the Biochart application system by Biostar Health care (Computer software) on the laptop. The task was to press the space bar as soon as the stimulus was presented. Average RT for both the stimuli (ART and VRT) were calculated using ten readings for each. Data obtained were analyzed.

Results: Our study shows that ART is faster than VRT for both males and females. Screen time with VRT has a moderate positive significant relationship (P < 0.001), while for the ART, it has a weak positive relation.

Conclusion: Based on our findings, it can be concluded that there is a positive correlation between screen time and RT. Screen time alone has a 21% effect on the RT as per our study. It also suggests that ART is faster than VRT. The females have a higher RT than the males in a similar age group.