Navmesh has become see-through?

I don’t know what I did, but my nav mesh has become see-through (i.e. nav mesh behind solid objects are showing through the object. See attached photo Imgur: The magic of the Internet). It is making it very hard for me to examine the navmesh… is there a setting I can tweak to revert back to the original display?

Its supposed to look that way. Its the 3d depth/transparency thats throwing you off, takes a bit to get used to.