So one thing I quickly noticed with my Vive is that glasses are a royal pain. You can use them fine but taking the headset on/off was kind of annoying. I had seen some people that had made their own lenses for the Oculus but didn't find any for the Vive so I set to work with my 3D Printer.
So here's a lens protector for the HTC Vive with optional perscription (or non-perscription) lens adapter. This is the lens portion of the piece. The Frame is here: https://www.shapeways.com/product/RPNDKQR66/vrprotect-frame
The frame snaps into the headset and the lens adapter attaches to the frame with magnets. The nice part about this is that it's easy to remove if you want to let someone else use the Vive. The Frame also acts to proect the lenses as they provide a bit of scaffolding above the lense surface. I have found that I can still wear my glasses with the frame installed and they cannot slide forward and hit the plastic Vive lens.
You need to get the magnets to glue into the frame and the lens pieces. The magnets needed are 1/8" diameter and 1/16" thick model D21B-N52 and you need 6 total.
I bought mine here: https://www.kjmagnetics.com/proddetail.asp?prod=D21B-N52
They are about 6$ shipped.
The glasses frames/lenses used are Zenni Frame 450021. I saw someone else used these for an Oculus model and thought they looked good (and cheap)
http://www.zennioptical.com/450021-metal-alloy-full-rim-frame-with-spring-hinge.html
They ended up being about 25$ shipped with polycarbonate lenses with glare reduction coating.
The lens holes are designed for a 40mm circle lens. For instructions to assemble the frame go to this video: https://youtu.be/Xb6jRee2Mpo
To see how to install this into the Vive, go to this video: https://youtu.be/nh7g7V6I4us
You can download and print this yourself from Thingivers: http://www.thingiverse.com/thing:1639833
Just for the sake of disclaimers, install and use these at your own risk. I'm not trying to get rich off this, just recoup some time spent and help fund my new printer.