How scratch resistant are the lenses on...
How scratch resistant are the lenses on the explorer with the spectron 4 lenses?
The glass is hard. Just don't drag on the rocks & you'll be OK. Typical Julbo quality.
The Spectron 4 is polycarb, not glass. Get the Alti Arc 4 if you want glass.
I've used these for a couple of years (polycarbonate lenses) and have no scratches. But, I do take good care of them so that plays into things.