Doing it on one eye per person would leave people with very unbalanced vision if it works great. That creates a QoL issue. Not enough understanding of the mechanism to then correct the other eye to the same level other than trying a "state at it for the same time approach".
maximum improvement was only 20%, for most none or less than 20% and only in dark enviroment, I don't think few weeks would really make any significant difference or discomfort which could not be reversed during next few weeks when you can exercise the other eye, so that's not really valid reason why not to do it this way
