The risks of LASIK vary from minimal to serious.  Fortunately, serious complication are extremely rare in well trained surgeon and staff hands.
The minimal complications include an epithelial defect (scratch).  The cells on the surface of the cornea are generally well adherent to the surface of the eye, occasionally in patients that are older or with dry eyes or excessive eye drops the cells become loose and dislodge.   Generally these heal overnight.
Other risks are overcorrection (too much response to the laser treatment), underresponse (less correction than desired), fluctuation of vision and dry eyes.  Most of these issues resolve over time.  If the final vision is unacceptable, an enhancement (retreatment) can be entertained.
Other risks include epithelial ingrowth (cells deposit under the flap and grow in nests)  or diffuse lamellar keratitis (inflammation under the flap) or ectasia (warpage of the cornea)