Floaters can have several different causes, but most commonly are due to (natural) degeneration of the vitreous jelly within the eye.
In themselves, they do not disqualify someone from undergoing refractive surgery like SMILE or LASIK.
However, occasionally they may be associated with other eye problems, such as retinal breaks.
As part of a routine pre-operative examination, with or without floaters, the doctor would carefully check the retina for any problems before proceeding with SMILE or LASIK surgery. If any problem is detected, that would have to be treated accordingly.
As long as the eye and retina is otherwise normal, one can safely undergo SMILE or LASIK even if there are floaters.
