Emmetropes and myopes were subjected to an hour of blurry movies (either through plus lenses +2.5D or reduced corrections for myopes; or through computer generated blur.)
The myopes’ eyes elongated in response to the myopic defocus while the ememtropes’ eyes got shorter.
Possible implications for us are that large attempted reductions (2.5D in this case) are counter-productive in myopia, but near-emmetropes or (very low myopes) might be able to benefit from larger amounts of myopic defocus stimulus.
Another possibility is that myopes have stopped trying to clear blur, but emmetropes do it all the time. [???]
The lines on the chart represent individual participants in the study. Almost all of the emmetropes are moving in the “correct” direction in response to the 2.5D myopic defocus stimulus (eyes getting shorter). Most of the myopes are getting worse after 60 minutes of 2.5 D myopic defocus. The computer-generated blur (middle column of charts) made everyone’s eyes worse except for one myope’s whose eyes got shorter.)