Assessment of visual function and structural retinal changes in Zen meditators

Purpose To evaluate whether Zen meditation (a mindfulness‐based practice) stimulates visual function and increases retinal and retinal nerve fiber layer (RNFL) thickness. Methods This cross‐sectional controlled study included 36 eyes of 18 meditators and 76 eyes of 38 age‐ and sex‐matched healthy non‐meditators. The average response of both eyes in each subject was analysed. All subjects underwent evaluation of high and low contrast visual acuity (using ETDRS charts), contrast sensitivity vision (CSV) using the Pelli Robson chart and CSV 1000E test, color vision (using the Farnsworth and L′Anthony desaturated D15 color tests), stereoscopic vision using the TNO test, and retinal and RNFL thickness using optical coherence tomography (OCT). Differences in visual function and RNFL thickness were compared between groups. Results We found that meditators exhibited significantly better visual acuity with the three contrast levels used, and significantly better contrast sensitivity vision (CSV 1000E) than healthy non‐meditators (p ≤ 0.05). Retinal and RNFL structural measurements did not differ significantly between groups. Ganglion cell layer thickness was moderately correlated with visual acuity, CSV, color vision, and stereoscopic vision (p ≤ 0.05; r > 0.6). Conclusions Visual function was enhanced in meditators without significant alterations in the retinal morphologic structure. Further studies are needed to determine whether there is a causal association between mindfulness and visual function improvement.