Keep Glasses from Slipping Off Neck Chain

My new glasses frames are thinner so they kept slipping out of the glasses necklace when I hung them on from my neck. I tried painting the sides of the frames (where the chain hooks on) with a little streak of rubber cement along the length.

It's clear, so it's unseen and it won't distort nor damage the new frames but it gives the thin smooth frames some "grip" to restrict the chain necklace from slipping off and dropping my new (fabulous) glasses! It can be rubbed off if needed since it's really just liquid rubber.