Here's a good link to some testing a player did. It illustrates quite well why many clubs, teams and fields do not allow mesh masks.
Mesh Mask No-No
We do not allow them on our field and I'm pretty sure no one in Calgary allows them either. JOC prohibits them for sure. There are those who will argue this, that and the other to be allowed to use them (Why would they sell them then? They use them in Asia, why not here?, etc.) What it really boils down to is, even if you were allowed to use mesh eye protection, would you really be willing to risk the permenent loss of your eyesight for a game? Hell, I used to wear unsealed ballistic glasses with a head strap (almost no fogging)...until I caught a burst come in through the top and actually felt bb's scraping against my eye ball. No damage, luckily, but I only wear sealed ballistic glasses/goggles now. IMHO, mesh goggles are a tragedy waiting to happen. For those who instist they will wear them anyway, go hard and I truely hope you don't have to learn to use a white cane because of it.