Trataka, yogic gazing, clarifies the mind, improving perception, cognition, and allowing easy access to Samyama (the interplay of Dharana, Dhyana, Samadhi), alowing one-pointed absorption necessary to doing deeper non-dual contemplation (Mahamudra) and to various siddhis of perception, influence, and manifestation.
Tratak practice is usually preceeded by a few minutes of warming exercises for the eyes, including cupping the eyes with warmed hands, then removing the hands and slowly sweeping the gaze up and down, left and right, diagonally, then following a thumb as the arm is swept slowly in a circle, Pete Townsend windmill-style, then sweeping the gaze between near and far.
Tratak practiced for even 3 minutes can make incremental improvements in clarity, focus, and perception. Building gradually day-by-day from 3 minutes to 10, or 15, or half an hour or more, will result Maintaining relaxation of face, eyes, and body, and simultaneous spinal/fascial tensegrity is key.
Slow yogic complete breathing should be maintained during the trataka practice.
After longer practices, face/head/neck massage and full body self-massage should be performed afterwards to re-embody, along with further eye exercises and gentle stretching and skeletal shaking. Otherwise, dissociation/depersonalization become risks with prolongued periods of practice.