Yes the real Mike does fix his glasses during that song and there is the same scene in the movie where Jeff Geddis is also using his index finger to fix the glasses. But then during the middle of the song, he brings his middle finger to fix his glasses. I mean it could just be he used that finger, but to me a looks a little like he's doing it on purpose lol.

It occurs during the little instrumental break from the song, one hour and 16 minutes (DVD time) into the film to be exact.
~*Diane*~

-No heartache's felt no longer lonely nights of waiting
finally won me happiness that's all rolled up in you-

*S*t*a*r*C*o*l*l*e*c*t*o*r*