LASIK surgery to correct myopia requires the creation of a corneal flap. Before the advent of femtosecond laser technology, a fully automated microkeratome was used to create the flap, and although the safety has been continuously improved, it is still felt to have some shortcomings. Complications related to corneal flap creation with the corneal knife, such as stuck flap, free flap, button flap, corneal flap eccentricity, corneal flap fragmentation, etc., which occasionally appear in the surgical procedures of some beginner surgeons, are the last thing that all myopic surgeons would like to see. In recent years, the technology of making corneal flaps with femtosecond laser has been introduced into China, and femtosecond laser equipment has been popularized in laser myopia treatment institutions in the United States, and in Taiwan, it has been popularized in two-thirds of myopia surgery hospitals and clinics. The sales of femtosecond laser devices in mainland China have also been rising year by year, indicating that Chinese ophthalmologists are gradually recognizing that femtosecond laser is about to become the mainstream technology for myopia surgery. Compared with microkeratome, femtosecond laser can produce very thin corneal flap, and the corneal flap thickness and diameter of the predictability is very good, the blogger has recently been in the keratome and the femtosecond laser these two ways to produce corneal flap comparison data collection, the results, although not the final out, but it has already shown that the femtosecond laser’s huge advantage, the following are the electron microscope magnification 20 times, 40 times, 80 times the The following is a comparison of the smoothness of the surface of the corneal stromal layer under electron microscope at 20x, 40x and 80x magnification respectively. We will find that at 20x magnification, the difference in smoothness between keratome and femtosecond laser cutting is not yet obvious. After 80 times magnification, the smoothness of the two cutting surfaces is completely different. The smoothness of the corneal stroma layer is directly related to the post-operative aberration of the eye, and a higher smoothness will result in a less severe post-operative corneal healing reaction, less new aberrations caused by the surgery, and better visual quality. I. Corneal cutting surface with electron microscope magnified 20 times: surface of corneal stroma layer cut by corneal knife (magnified 20 times) surface of corneal stroma layer cut by femtosecond laser (magnified 20 times) II. Corneal cutting surface with electron microscope magnified 40 times: surface of corneal stroma layer cut by corneal knife (magnified 40 times) surface of corneal stroma layer cut by femtosecond laser (magnified 40 times) III. Corneal cutting surface 80 times: surface of corneal stroma layer cut by keratome (80 times magnification) surface of corneal stroma layer cut by femtosecond laser (80 times magnification)