If, like me, you've had your furry friends destroy the top of your lens and are looking for a protective cover to use prior to baseplating - look no further. This is a very simple hollowed out sphere that you can glue over the lens (I still put a layer of kwik cast over the lens first). Unlike a PCR tube cap, there is really nothing for the mouse to grab ahold of. I've attached an image of a mouse immediately before baseplating that had the cap for 4-5 weeks. The top of the lens was in pristine, perfect condition.
For printing, I printed on a Form3 at 25 uM resolution. Wash well. At the end of the lens implantation surgery, I just used loctite gel control super glue to secure it to the headcap. If you have concerns about glare of the super glue you can apply black nail polish before baseplating.
May all your lenses remain intact,