From a Cleansing Kriya to a Concentration Technique

What trataka was originally for and what it is mostly used for today are two different things, and the gap between them is a useful case of a physical practice being kept while its stated purpose changed underneath it. The classical hatha yoga texts, the Hatha Yoga Pradipika and the Gheranda Samhita among them, group trataka with five other cleansing procedures, the shatkarmas, alongside practices for clearing the nasal passages, the stomach and the bowels, and describe its benefit in almost entirely physical terms: it is said to cure eye disease and induce a specific clarity of vision, and the texts treat it as bodily preparation clearing the way for pranayama and meditation rather than as a meditative technique in its own right.

Modern yoga and meditation teaching, particularly as transmitted through twentieth-century figures who reframed hatha yoga for a psychologically minded Western audience, has shifted the emphasis almost entirely onto the second half of the exercise, the closed-eye retention of the after-image, treating that moment as the point of the practice rather than an incidental effect of eye fatigue, and presenting trataka chiefly as a concentration and visualisation training exercise comparable to other one-pointed attention techniques rather than as a purification of the eyes. Contemporary teachers rarely cite the disease-curing claims of the classical texts at all, which makes trataka one of the clearer instances in yogic practice of a technique surviving intact while the tradition's own stated rationale for it was quietly replaced by a different one better suited to how it is actually being used now.