[...all errors of refraction can be cured by relaxation. All methods
of treatment, therefore, are simply different ways of obtaining
relaxation. And because it is impossible to relax the eye muscles
without relaxing the mind - and the relaxation of the mind means the
relaxation of the whole body - it also follows that improvement in the
eyesight is always accompanied by an improvement in health and mental
efficiency...]

- W.H. Bates, July 1919, "Better Eyesight"