When the mind is still our internal vision becomes strong and we can experience peace. There is a direct relationship between our state of mind and our connection with self.
In yoga we understand mind as a vehicle that we drive. The mind should not be driving us. Thoughts are invisible but very real as they lead to action. When the mind is distorted, it is like an ocean with waves and leads us to a distorted vision where we misidentify, feel disturbed, and uncentered.
Instead, we want to control the mind so we can be harmonious. Through the practice of yoga and self discipline we can find what we really want.