Tratak
Tratak is a method of meditation that involves starting at a single point such as a small object of meditation. It is a divine gaze the restless mind too comes to a halt.
There is fix attention on a symbol or yantra, like Om, a black dot, The image of deity or guru, A flame, a mirror or any point and stare at it. Put candle should be 3 to 4 feet away. The flame level with the eyes sees the mirror whenever the eyes begin to water. I said there is no need for any scientific, Guru, and any who are an experience. You have to sit very stable and see without a blink of your eyes. That's enough. Then you have to get there everything which is the power of you.
It is the improves eyes muscles and might improve vision. This practice of Tratak Sharpens our minds and develops our inner ability to stay with one idea, image or concept for greater lengths of time.
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