Firstly, myopia surgery essentially involves thinning the cornea by cutting it, which is like transferring the degree of myopia onto the cornea itself. Let's first talk about the layering of the cornea. From front to back, the cornea is divided into five layers, generally consisting of the epithelial layer, anterior elastic layer, stromal layer, posterior elastic layer, and the corneal endothelial layer. Among these layers, the stromal layer is the thickest, about 500 microns, accounting for over 90% of the total corneal thickness. Therefore, during myopia surgery, the main area of cutting is in the stromal layer of the cornea.