[IIsi50MHz]

This becomes difficult for someone whose eyes are mismatched.

Would practicing with one eye properly covered, to have low enough lux to prevent the natural feedback mechanism which causes myopia[1], seem impractical?

[1] Extended or frequent exposure to low-contrast input causes lengthening of the eye, and can be irreversible after two weeks[2]. Seems to involve eye and visual cortex, and to not occur if the eye has no connection to the visual cortex. I'm not aware of any similar mechanism to account for far-sightedness.

[2] Consequently, nightlights and other light sources which shine into a sleeping area may be counter-indicated.