Full femtosecond and semi-femtosecond have their own advantages and disadvantages, the difference between the two are mainly the surgical method, the laser used, applicable to the population and so on. 1. Surgical method: the full femtosecond surgical method is to make a small incision in the cornea, and then use the femtosecond laser to cut a lens in the cornea, and then artificially remove the lens, which is the degree of myopia. Semi-femtosecond is to use femtosecond laser to make a corneal flap on the cornea, and after the flap is lifted up, excimer laser will be used to remove the degree of myopia. 2. Laser used: full femtosecond is to use all femtosecond laser for myopia correction surgery; semi-femtosecond is to use femtosecond laser combined with excimer laser for myopia correction surgery. 3. Applicable people: Full femtosecond surgery is mainly applicable to myopic patients with myopia of less than 800 degrees, suitable for military personnel or athletes. Full femtosecond surgery causes less damage to the corneal nerves, thus the probability of dry eye after surgery is also lower. Semi-femtosecond surgery corrects a much wider range of myopia and is typically used for patients with less than 1,000 degrees of myopia. The exact type of surgery to be chosen requires a detailed eye examination and the guidance of a specialist to choose the right type of surgery for your situation.