Yoga and Kriya for Visual Function and Eye Strain in Children with Low Hyperopia

Abstract

Low hyperopia adds to the accommodative load of near work, and heavy screen use strains children’s eyes, but the effects of yoga-based eye practices are unclear. In this assessor-blinded randomised controlled trial, 60 children aged 11–15 years with low hyperopia (spherical equivalent +0.50 to +1.00 D) in Chennai, India, were allocated to a yoga and kriya programme (n = 30) or their usual routine (n = 30). The 12-week programme, delivered four days a week, combined loosening exercises, suryanamaskar, 30 minutes of candle trataka, pranayama and relaxation. Amplitude of accommodation (AA), unaided distance and near visual acuity (VA, NVA; logMAR), extraocular muscle (EOM) excursion, a study-specific digital eye strain (DES) score and cycloplegic spherical equivalent (SE) were compared by baseline-adjusted analysis of covariance, with Holm correction for the six outcomes. All children completed the study. Compared with controls, the yoga group had higher AA (adjusted difference 1.03 D; 95% CI 0.76 to 1.30), better NVA (−0.058 logMAR; −0.073 to −0.044), greater EOM excursion (0.77 mm; 0.54 to 1.01) and lower DES scores (−4.9 points; −6.5 to −3.3); all p < 0.001. Distance VA also differed (−0.036 logMAR; −0.051 to −0.022; p < 0.001), but the near and distance acuity differences, about three and two letters, were within usual test–retest variation. Refraction did not change (SE difference −0.002 D; −0.019 to 0.016; p = 0.86). In exploratory analyses, physically active children had less eye strain at baseline, and gender, diet, physical activity and media use did not significantly modify the effects, apart from a nominal gender interaction for SE (p = 0.042) with no significant change in either gender. A 12-week yoga and kriya programme improved functional measures of accommodation, near acuity and ocular excursion, and symptom scores, in children with low hyperopia, but did not change their refractive error. The changes were statistically robust, but their clinical importance is uncertain, and they need confirmation in larger, independently conducted trials with validated symptom measures and longer follow-up.