Laser eye surgery
The cornea is a window of the eye. In laser eye surgery the cornea will be reshapened by laser ray. By laser can be corrected farsighteness (myopia), longsighteness (hyperopia) or antigmatism. Usuallu correction is possible from level +3 - -10. On the other hand from those numbers the sight can be corrected very near of 0 sight. The final estimate does the doctor.
In Lasik surgery there will be opened a flap on the eye and laser correction will be done to stroma bed. In the end the flap will be closed.
PRK method. At first the epithelium is removed from the eye and after that the laser correction will be made to the stroma bed.
In Smile surgery the laser correction is made to the stroma bed. Epithelium will not be destroyed. Finally after operation small lenticule is taken away under the epithelium from smole hole. This hole is made to epithelium.
All the other surgery methods are same or very similar. Only the marketing name can be different.
Here is a simulation about PRK, Lasik and Smile.