[davidfv1]

This exact play is in the 2003 NFHS Football Case Book.
Page 54, Rule 7, Play 7.5.10 Situation C:

"Ruling: Hindering an opponent's vision without making an attempt to catch, intercept or bat the ball, is pass interference even though no contact was made. This is the only situation in which there may be pass interference without contact."

I hope this helps..

David