Trāṭaka
Trāṭaka (Sanskrit: त्राटक "look, gaze") is a yogic purification (a shatkarma) and a tantric method of meditation that involves staring at a single point such as a small object, symbol or yantra such as the Om symbol, black dot or candle flame. == Historical and Traditional Background == Trāṭaka is named among the six cleansing techniques (ṣaṭkarma) in the classical yogic manual Haṭha Yoga Pradīpikā — where it is defined as “gazing steadily at a small mark until tears flow,” and is said to eradicate eye diseases, fatigue, and sloth.