Change in refractive status and pupil size during different yoga posture among healthy subjects

The purpose of this study was to find out the effect of different yoga postures on the refractive status and pupil size among healthy individuals. The cross-sectional study involved 27 healthy individuals with a mean age of 19.9±1.69 years. The procedure was explained to the subjects and written informed consent obtained. Structured yoga training was given for all participants to get them to perform five yoga postures. On completion of training, refractive error and pupil size were measured for each subject using photo refractometer at rest and while performing yoga. Comparing refractive error measurements with all the yoga postures no statistical significant difference observed, but when the mean value of pupil size baseline reading compared with each yoga postures, we found a significant change in pupil size during the asana (p<0.001). The study shows a significant increase in pupil size across yoga postures as compared to prone position. There was no change in the refractive status across all yoga postures.