Why opticians claim that myopia is irreversible?

Actually, my vision impoved (confirmed by an optician, but she thinks that's a concidence) after some vision therapy. It's hard to believe that myopia increases with bad habits but cannot improves with good habits.

I mean irreversible through vision therapy.

Jose DeSilva, creator of the DeSilva Mind Control system, claims to have corrected his own myopia through auto-hypnosis, as have many of his students. I haven't tried and can't verify it, just throwing it out there.

I think what you meant to say is that myopia cannot be reversed through vision therapy. An optician is the first one who will tell you it can be reversed through surgery. The body does have an incredible ability to regenerate itself, but years of bad habits inflicted on such delicate tissue would seem to be too much even for that.

The vison therapy may actually have improved the strength and coordination of the eye muscles but myopia is a result of an eyeball that is too long. No amount of therapy will change that.

Do you know for a fact that "opticians claim that myopia is irreversible" or was that just what this one doctor said? Be careful of making blanket statements.

There are laser and non-laser techniques that can improve many degrees of myopia to near perfect vision. You may want to investigate this to find out if you'd be a good candidate. These procedures are, unfortunately, rather pricey but they are considered to be safe if done by an experienced surgeon.