(1) the corneal thickness pre-and postoperatively, as well as laser method, (2) the ablation depth of the laser, (3) the pre-and postoperative refraction objectively and subjectively, (4) the values of the actual glasses.
That's what they will check and furthermore they need to see a proof that you had not exceeded the +/- 3 diopters.
I've just read some reports on a german pilot board where they failed because of their eyes, there are probably a few who made it.