Craig F. Beyer, DO

This usually causes no long-term problems so I wouldn't worry about the eye rub.  However, I'd be more concerned regarding the shower and getting tap water in your eyes.  Tap water is not sterile and in fact contains fungus and protozoans such as acanthamoeba which can cause serious eye infections especially while the surface of your eye is not healed after PRK.  It's ok to take a shower, just make sure you cover your eyes well with a towel so that the water does not run directly into your eyes.  

Although LASIK can be performed off label, I wouldn't do it for a 13 y.o.  My main concern is that younger people, especially those under 18 years of age, have very placid corneas.  Placing and incision in this young of cornea while making the LASIK corneal flap puts the cornea at risk for instability and later ectasia.  That said, however, if all other factors were normal and there was plenty of corneal thickness, I would consider PRK instead of LASIK since no corneal flap is necessary for PRK.  I would seriously consider this for a 13 yo who is highly anisometropic (and thus unable to wear glasses) and who would be unable to wear a contact lens safely.

Of course keeping your eyes closed as much as possible would help your dry eyes but, not very practical especially if you have to work to earn a living.  We use many treatments for dry eyes including punctal plugs, restasis, and serum tears which typically, all help solve the problem better than over the counter tear drops.

In reality, the LASIK flap is always there.  I have patients over 10 years after LASIK and I can still dissect their flap free for an enhancement if necessary.  That said, the best analogy would be like preparing chicken for dinner - the skin on a chicken will never fall off on it's own but it's not hard to remove with the proper tools.