The smart contact lens system hereby proposed, integrates a number of electronic, electro-optical or optical components on the contact lens substrate. The system, inter alia, is arranged to identify and track changes in pupillary response due to mental task engagement, also known as task-evoked pupillary response. To this end, the system proposed tracks a variety of conditions affecting reflexes such as pupillary reflex or accommodation reflex, in order to compute the extent of pupil dilation attributable to the mental task engagement. Another aspect of present invention is a smart contact lens system, which minimizes pupillary reflex caused by light by controlling the amount of light entering the eye. When pupillary reflex is non-existent, computing a task-evoked pupillary response becomes a much easier task.