I had LASIK done three weeks ago, and I rubbed my eye in my sleep. My eye is sore, and stings with drops. Did I mess up my flap?

It’s true that you need to be very careful about eye rubbing after surgery, but it’s unlikely that you caused any major damage to the flap 3 weeks out. You would have far more eye pain if the flap sustained any real damage from the rub. That said, any time you think you injure your eye it’s a good idea to get it checked out by your surgeon. You probably caused a small scratch that then made the drops sting upon instillation. These  types of injuries take a day or two for the discomfort to go away but two full weeks for the eye to be fully repaired from it. Make sure you continue preservative-free artificial tears 3-4x per day for the next couple weeks.