Su Tung-ping explains how patients undergoing phototherapy are exposed to light of 10,000 lux (20 times the typical intensity of light indoors). When the eyes are exposed to this much light, it triggers the body's production of melatonin, which eases the way to sleep.
蘇東平指出，「光線治療」是使用一萬個光度（室內光的二十倍）的光照機照射，經由眼睛吸收影響松果體，進而影響退黑激素的分泌，使人產生睡意。