FIELD : medicine.SUBSTANCE : group of inventions relates to medicine. Device for detecting reflected light in the form of a contact lens comprises one or more light-receiving elements for receiving light, wherein the light is reflected from the sclera and the iris of the eyeball; and a signal processing module for detecting the amount of light received by said one or more light-receiving elements. Method for detecting reflected light includes : a step of receiving light, in which light is received, using one or more light-receiving elements, reflected from the sclera and iris of the eyeball; and a detection step in which the amount of light received from said one or more light receiving elements located in areas of the detection device is detected by the signal processing module.EFFECT : use of this group of inventions will improve performance.20 cl, 26 dwg, 3 ex