I was looking at my scopes last night and they all have spring assist flip open caps. It occured to me that PVS14's, Pvs15's, PVS7's, etc all have daylight filters that are held on by string and flop around like wet noodles in a hurricane. I was starting to think if there is flip daylight filter caps out there. do they exist or is this a bad idea to have on night vision?