Yes, it's a myth in the sense that you would need to wear the glasses several orders of magnitude longer and/or consistently for there to be any negative effect

Yes, it's a myth in the sense that you would need to wear the glasses several orders of magnitude longer and/or consistently for there to be any negative effects. Some people seem to think that even looking through the glasses will unleash demons into the healthy eye. Modern research does point in the direction of the eye remodelling itself based on what kind of input you give it on a longer scale, though. This includes the amount of light seen during the day and whether it is able to focus rays or not. There are indications these play a role in the development of myopia.