Are ultraviolet rays dangerous? This is the question addressed by the leading dermatological experts who compare their wide clinical experience in this book. It has now been established that ultraviolet rays provoke erythema and can cause considerable damage to blood vessels. But what is their precise impact on the occurrence of premature ageing and cancer of the skin, and other serious consequences? The specialists contributing to this work report on their observations and give objective and reasoned opinions on this question. Their explanations are rounded out by many colour illustrations and diagrams.