Admittedly, natural ultraviolet radiation (UVR) helps 60 per cent of acne patients temporarily but this  is a therapy that this author no longer prescribes. Although UVB  is  used fairly  extensively  in some European departments  good clinical studies  are  lacking. The inconvenience of repeated visits for such therapy would be not worthwhile for most patients. UVA  probably does not  influence acne except for the production  of a cosmetic  tan.