Vision is about creating an image of reality. Two things are important here. A vision is something concrete you can see: an image, possession detail and continuity in time. A vision is something you create; it is an act of the mind that produces something that was not there before.
Vision is connected to purpose. Vision means creating an image of the world with the specific purpose of changing things so that the image becomes reality. Vision is about changing the world, that is vision VISH-style: Vishion.
There is an esoteric power to this idea, given the following definition. According to Aleister Crowley, Magic (or Magick, as he preferred) is:

… the science and art of causing change to occur in conformity with will

In changing the world in accordance with your vision it is important to get the purpose right. A right purpose is a purpose that is:
- Truly and authentically yours
- Derives from your deepest values
- Is in balance with the world
To elaborate upon this last point: Nature has a tendency to balance things out, it is a fundamental principle. All actions have consequences, and they must of necessity be included in your vision. You must accept the results of your actions, no matter how unexpected. Much of this is common knowledge, contained in proverbs like: sow the wind; reap the whirlwind, and principles like the Dialectics of Progress (initial advantage leads to a disadvantage as developments progress).

In a different era the central philosophical question related to the individual was:
What am I?
Who am I?
This question can now be reformulated:
What do I (really) want?