I'm considering using a Flexi piezo vibration sensor for detecting rapid eye movement 
or R.E.M(wiki).
However I've noticed that flexi piezo sensors can produce a very high voltage of around +/- 90v!!
Is this something to be concerned about especially as its so close to my eye / head / brain / face?
Component in question:Piezo Vibration Sensor - Large - Proto-PIC
Thanks for your help
James 