It does not matter if you do it right-left or left-right.
All these technicalities are simply vague guidelines to give you an idea of how to do it.
The real results happen because you exercise your eyes and energize them in one way or another.
There is no exact/right way to do it. Just do it the way you feel or the way it comes. As long as you do exercise a bit, results do come!
Remember to focus on fun, variation!
Your mind tends to get bored if forms are too fixed.