During the four-week study period , 89 patients ( 67 females ; 22 males , aged 22-65 , mean SD age : 43.2 10.9 years ) suffering from SAD were randomized to receive a 12-min daily dose of photic energy of one of three intensities ( 1 lumen/0 .72 mW/cm ( 2 ) ; 4 lumens/2 .881 mW/cm ( 2 ) ; 9 lumens/6 .482 mW/cm ( 2 ) ) via the ear canals .