Two. A vacuum ring is positioned around the cornea, which serves to stabilize the eyeball and likewise functions as a platform for the microkeratome. When vacuum is activated, the eyesight results in being hazy and tension on the eye is felt. LASIK isn't advisable for patients with keratoconus, given that https://lovelydirectory.com/listings1004314/the-greatest-guide-to-lasik-eye-surgery