Abstract: There is provided a method and an apparatus (300) for modifying parameter values of an optical treatment. The apparatus (300) comprises an interface (306) configured to receive first information related to the parameters of an optical treatment for improving the mental or physical condition of a user (102), and to receive second information comprising at least one indicator (800A, 800B) of whether the optical treatment is successful or not. The apparatus (300) further comprises a processor (302) configured to apply at least one predetermined weighting coefficient (804A, 804B) to each of the received at least one indicator (800A, 800B), to combine the weighted at least one indicator (800A, 800B) to a joint indicator value, and to determine whether the parameter values of the optical treatment apparatus are to be modified or not, on the basis of the received first information and the determined joint indicator value.