During the four-week study period , @ patients ( @ females ; @ males , aged @-@ , mean SD age : @ @ years ) suffering from SAD were randomized to receive a @-min daily dose of photic energy of one of three intensities ( @ lumen/@ @ mW/cm ( @ ) ; @ lumens/@ @ mW/cm ( @ ) ; @ lumens/@ @ mW/cm ( @ ) ) via the ear canals .