So how do we properly wear mesh masks? We know that they're supposed to prevent fogging but if we still use goggles underneath, then why use mesh as an alternative eye protection? For us it's a combination of using the mesh for lower face protection and ballistic goggles/glasses for eye protection, preferably those with vents to help minimise fogging.

Here's Evike.com doing a test of the mesh masks.
 
"We've received a lot of questions on mesh masks. Do you need to wear goggles underneath them? Yes. These tests were done using a variety of BB weights, brands, as well as different velocities. Be Safe."