The present application discloses an apparatus for protecting a user's eye from blue light radiation, the apparatus includes a radiation detector configured to convert blue light from a light source into a photo voltage having a voltage value; a processor coupled to the radiation detector and configured to calculate a cumulative radiation intensity based on the voltage value cumulated over a time interval, and to compare the cumulative radiation intensity with a threshold value; and a controller coupled to the processor, configured to adjustably control blocking of at least a portion of blue light from the user's eye when the cumulative radiation intensity exceeds the threshold value.