Trataka is one of the Shat Kriyas (Six Yogic Cleansing Processes).
It is the practice of focusing on a fixed gazing point. It involves looking at an object, usually a flame, small dot, the moon, rising setting sun, or yantra (specific geometric diagram) without blinking. Focusing on these external objects helps to train the mind to be able to focus on internal points, used as internal trataka as well as in other concentration (meditation) practices.
How does it work? When you think, your eyes move rapidly. By stopping this movement trataka forces us to slow down or pause the thought processes, allowing the mind to become calm. This is a type of Pratyahara (see 8 limbs of yoga) technique as you are directing all of your energy into the sense of seeing, and withdrawing the other senses.
Regular practice of Trataka can help to focus the mind in other areas of life too, by training yourself to concentrate, you can become more efficient.
You might be wondering how it is a ‘cleansing process’, well, by resisting the temptation to blink, and allowing the tears to flow freely, we clean not only the surface of our eyes (which could be done with eye baths) but our whole visual system. It also trains the intellect to be able to focus on (and complete) one thought, which helps to break the unhelpful repetitive thought loops in the head, and prevents them from building up as mental toxins.
You will need
(If it is difficult for you to sit comfortably on the floor sit on a chair with your spine straight and have the candle on a higher surface)
People suffering with psychic problems such as schizophrenia or hallucinations may want to avoid this and other strong 3rd eye meditations. If they wish to do this practice they should seek the guidance of a trusted and knowledgeable teacher.