It seems like sort of hit and miss, we have a pair of binoculars that we brought in, and are friends brought down a drone, which I don't think is legal. But it probably depends on the mood of the border gaurd.
Since there is a descent chance of them getting confinscated, lost or broken, my recommendation is that you buy a cheap pair to bring, that way if you do lose them, it's not as big a deal.
also don't bring the binocs in their original package. Anything in a brand new box will get taxed extra because they think you might be trying to resell it.
Our group had some duffle-bags full of phones, laptops etc. but they didn't really care that much, but the guy in front of us had a bluetooth speaker that was brand new, so they made him pay extra.
Overall, probably 25% chance of being confinscated
