Ignotum

Hi old-fashioned

Maybe a kind of spray-on adhesive, and what if the spray-on adhesive was opaque, then you get double protection!

Actually, then you would ONLY need the spray-on adhesive, just spray a healthy amount on the lens (the most light sensitive part) and you’d be done

Now if only there existed a product like that that is available in pretty much every hardware store and hobbyshop…

That joke was a bit derivative