All lasers differ in various aspects: Technological development, which is one of the most important factors, as it offers better results and lower risks in general. Price, which is directly related to the technology used in most cases. Technical support and research programs that enable continuous development and improvement of correction techniques. Not all lasers are approved by the FDA (Food and Drug Administration) of the United States. The age of the equipment allows for assessing technological development and evaluating the risk-benefit ratio of surgery.