Vision therapy is also known as Optometric Vision Therapy or VT.
It is a planned process of exposing a patient to increasing complexity of visual experiences to develop, improve or enhance visual performance. It includes in-office visits to teach each skill, often weekly, with home exercises to master the skill.
Vision learned, so it is an active, growing process that can improve or change throughout our lives. Like any developmental process, some people have learnt better than others, and visual performance varies between people. Like other muscle and body systems, we are not stuck with what we have now, and we can learn to have different ways of seeing.
I have included some interesting web links below:
Another TED talk by Cameran McCrodan, an optometrist who speaks about vision development and vision (and credit for the summary of vision on the left of this page). Another summary of essential visual skills is listed here.