PORTABLE ILLUMINATION DEVICE FOR MODIFYING CIRCADIAN RHYTHMS

摘要

A portable light treatment device is capable of delivering the illumination which is sufficient in amount but mild to the subject's eyes fo r assuring effective light treatment without unduly annoying the subject. The device has a surface illuminating unit having an effective surface regi on of at least 15 cm2 which emits a visible diffused light of reduced luminance variation. The light is selected to give an illuminance of at least 2000 LUX measured at an eye position of the subject. A mount member is provided to mount the surface illuminating unit to a portion adjacent to eye s of the subject to direct the diffused light to the eyes of the subject. Thus arranged portable illumination device has an advantage of delivering sufficient amount of the light to the subject's eyes without dazzling the subject and therefore administering effective treatment without imposing severe restrictions to the subject's daily activities. Preferably, the diffused light is selected to have an average luminance of from 1,000 to 4,000 cd/m2 and have a maximum luminance of less than 6,000 cd/m2 in order to minimize the dazzling effect. Further, the ratio of a maximum to minimum luminance appearing in the effective surface region is selected to be less than 2.5 and difference in luminance between any two points spacedby 2 mm is less than 100 cd/m2 in order to further minimize the dazzling effect.< /SDOAB>