If you are interested on this ability and want to try it here are some initial tips to activate the ciliary muscles, it does take a while but with enough practice you will manage.
Place your finger in front of your eyes and then focus your vision at it, although your eyes cross you will be able to see the background blurry.
If you then move your finger away and manage to hold the blurred vision without crossing your eyes, you will feel the ciliary muscle a bit tense and relaxing it would refocus your vision. Being able to switch between both will give you full control.
Please let me know if you manage and share your experience.
Place your finger in front of your eyes and then focus your vision at it, although your eyes cross you will be able to see the background blurry.
If you then move your finger away and manage to hold the blurred vision without crossing your eyes, you will feel the ciliary muscle a bit tense and relaxing it would refocus your vision. Being able to switch between both will give you full control.
Please let me know if you manage and share your experience.