To tell you the truth, I don’t know.
I do believe that combined with other healthy habits, this could do the trick but I am not sure. i still have to experiment.
The key with 5 min/day is that it is relatively easy to perform. Longer eye training sessions require much more focus and could be more challenging to maintian on the long term.
Remember that you want to establish a training rhythm you can easily maintain on the long term.