Generally zazen practitioners meditate with their eyes open–if not wide open, then partially open with a soft focus. Eyes are directed forward and slightly downward. An unexpected finding of this study is that zazen meditators exhibit much lower rates of eye blinking when they are doing zazen, as opposed to just sitting quietly.
The Muse headband automatically records eye blinks, so this was an easy comparison to do. During the September osesshin, four subjects were asked to do zazen for the first 20 minutes, then to stop meditating for the final 5 minutes of the recording session. A group of nine subjects were asked to sit quietly for 5 minutes without meditating, then do zazen for 15 minutes, then stop meditating for the final 5 minutes.
The time series graphs below show examples of recordings in which eye blinks are superimposed upon absolute alpha band power.
After normalizing blink rates to blinks per 10 minutes and consolidating results for 13 subjects , we have the following result:
Among 13 subjects, the average blink rate during zazen was 9.9 blinks per 10 minutes, while the rate during sitting quietly without meditating was 161.4 blinks per 10 minutes. Eye blinking during zazen was reduced by a factor of 16 compared to sitting quietly without meditating.