In the below photo, notice that the Greensboro News & Record shooter covering an April 2012 Tea Party rally in Greensboro, N.C. is wearing glasses - whether needed for vision or sunglasses or whatever - and they are held on his head by a piece of rubber tubing.  I used a thing from Wal-Mart’s fishing department to hold my glasses on my head - and it’s inexpensive and floats.
   Stories you will shoot will have you dealing with real live idiots - even if only drunk guests at a wedding!  Rallies may degenerate into riots without notice - regardless of the ideological orientation of the rally; one counterdemonstrator throwing something may - if by accident - hit you in the face.
   So - even if you wear contact lenses or don’t need glasses - get real glasses or sunglasses made by a local eyewear place, with large thick lenses (unlike the shooter in the photo) to maximize protection.  The lenses should be polycarbonate - the eye-doctor industry’s name for the Lexan used in bullet-resisting shields - so it won’t break into little pieces that end up in your eye.  Major benefit: such eyewear can keep you shooting that story even if your eyes wouldn’t have been injured at all.

Greensboro (N.C.) News & Record shooter covers Tea Party rally, April 14, 2012, Greensboro.
Note eyeglasses and tubing holding them
on his head.