METHOD

Sample

There were 2 groups of subjects (with ages ranging from 17 to 22 years). Each group had 18 subjects, of whom 3 were females. One group participated in a 10 day residential camp in yoga. The control group, like the yoga group were university students.

Testing Procedure

Critical flicker frequency was measured using the apparatus fabricated by Anand Agencies (Pune, India), which has a red light stimulus (6mm in diameter) with intensity of approximately 06 mw/cm2 at a flash frequency from 12-95 cycles per second. Each subject was tested individually with binocular vision. The apparatus and subjects eyes were kept on the same line of vision and were 50cm apart. During the experiment all overhead lights were switched off except one 60w bulb to maintain a constant background illumination.

 Assessments were made for both groups ('yoga' and control) at the beginning and end of 10 days. During the 10 day period the 'yoga' group received training in yoga, whereas the control group did not receive such training and carried on with their routine activities. The initial and final values were compared for significant differences using Wilcoxon's paired signed ranks test.

The yoga group received 10 days training in asanas (physical postures), pranayarna (voluntary regulation of breathing), kriyas (cleansing techniques including visual focusing exercises used to improve visual acuity and mental concentration), meditation, devotional sessions, and lectures on the theory and philosophy of yoga. This programme took approximately 8 hours a day.