I have a ZR1 half helmet, and it doesn't generate much lift at all below 110 MPH. I used to have a wermacht style lid, and that would fly like a bird above 20 MPH.

Most lids these days, except for some custom fit racing types are made to fit around glasses. Well, maybe not the kind Elton John wears....

Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python