Effect of Trataka on Visual, Cognitive, and Psychophysiological Outcomes: A Systematic Review and Meta-Analysis

Objective: A complementary and alternative healthcare practice such as Trataka, a Yogic visual concentration technique (YVC) rooted in Ayurvedic tradition, links cognition, visual, and psychophysiological well-being. This meta-analysis aimed to evaluate the moderating factors, including variations in study design and intervention protocol, to understand the efficacy of YVC across multiple domains. Methods: Systematic searches of eight scientific databases obtained 34 studies from 280 records until December 2025. Based on task scores, meta-regression and statistical heterogeneity were assessed using a random-effects model to obtain standardized mean difference (SMD) and risk of bias (RoB). Results: A pooled meta-analysis showed a significant YVC effect over control conditions across visual, cognitive, and psychophysiological domains (SMD of 0.92, 95% CI [0.44, 1.41]), with substantial heterogeneity (I2 = 74%) and a wide prediction interval (−0.22 to 2.07), which indicated that the true effect size could range from negligible to large, while extending to future studies. Meta-regression across the nine cognitive studies (K = 4 for each study design; k = 1 outlier) revealed no statistically significant duration–response relationship between session length and cognitive outcomes. RoB assessments indicated unclear to high risk among included studies. Discussion: Our results indicate that regular YVC practice could be associated with potential benefits for ocular and cognitive wellbeing, and for stress reduction, aligned with Sustainable Development Goal 3. However, given substantial heterogeneity, methodological limitations, and RoB concerns among included studies, these findings should be interpreted cautiously. Standardized protocols, larger controlled trials, and neuroimaging approaches are needed to more precisely characterize YVC-related effects.