VisuMax Full Femtosecond Laser System: This is the fastest femtosecond laser system in the world at present, and the laser emission frequency is as high as 500Khz, which is faster than the Intralase FS femtosecond laser in the United States and the Leonardo da Vinci femtosecond laser in Ziemer LDV in Switzerland. This means that the time for making corneal flap is shorter, the thermal effect between corneal layers is smaller, the time for attracting eyeballs by negative pressure is shorter, and the time for retinal traction and fundus ischemia in LASIK surgery is shorter, which is safer and more efficient.