That's interesting. I hadn't realised that the extra-ocular muscles were the focus (groan) of the Bates method.
I'll make a comment/recap, getting to the point at the end.
I am satisfied that I can use these muscles to effect a fine-tuning of my disappointing replacement lense... (+1.5 cyl.)...but realise that it is little more than a party trick.
I have written quite a bit about the pain that I suffered when these muscles went into spasm over a period of weeks. I hypothesized that it was because my brain was trying to process round a new huge floater. (post PVD) and mentioned that as a child I had, quite unconsciously, used this method to overcome a slight error in focus. Presumably this old tactic was stored away somewhere in my subconscious and came out to cause havoc over 50 years later.
In desperation, I went to see 3 different top surgeons while all this was going on. Never was the concept of these muscles causing the pain suggested.
Despite being passionately against the use of Valium, I used it as a diagnostic tool, and found that a minute amount switched off the spasm, stopping the pain and letting my eyes focus perfectly. I cannot imagine what would have happened if I had not thought of this.
The point being. Although I'm sure not many people are likely to react in this way, just perhaps, a few others will. Training these relatively large muscles into extracurricular activities, just may have hazardous side effects.