Femtosecond laser is the original service in the military “mysterious light”, as early as before the market, the United States and Britain and other developed countries have been in the fighter pilots to carry out femtosecond flap laser surgery, the special soldiers are given priority to accept, can improve the fine imaging ability, enhance combat effectiveness! In fact, femtosecond laser is a kind of infrared laser (wavelength 1053nm; excimer laser is far ultraviolet, wavelength 193nm), its pulse duration is ultra-short, only a few to hundreds of femtoseconds (1 femtosecond is equal to 10-15 seconds), according to the principle of power=energy/time, the lower energy can instantly produce very high power. The femtosecond laser passes through the outer layer of corneal tissue without damage and focuses on the corneal stroma (1 μm space), generating plasma, which expands continuously at ultra-high speeds and produces a light burst that separates the tissue, forming tiny bubbles (5 μm) containing CO2 and H2O, which are linked together to form a plane of separation, thus creating a horizontal, vertical, or inclined keratoconus, and completing the flap. Flap creation. With the continuous progress of science, the introduction and application of femtosecond laser technology has brought the development of LASIK surgery to a whole new stage. With laser flap making, its precision is more than 10 times than that of traditional corneal knife, and it can cut thinner corneal flap. It has also realized the technical leap from “knife” to “no knife”, and is regarded as the “star of tomorrow” by the ophthalmology industry.