If a leather cord irritates my skin, is braided nylon likely to be more or less irritating?

No, guys, this is just about eyeglasses. Sorry. Simmer down.

I have a (very unglamorous) thin leather cord attached to the eyeglasses I wear all the time. They’re constantly on and off, and this is my best way of keeping track of them.

At least, it’s better than spending a significant part of every day trying to find where I left my glasses. When I take them off, I don’t absent-mindedly put them down somewhere—they’re right on the cord around my neck. So mostly I don’t lose them like this any more. (And I do still miss @FutureMemory.)

But the leather cord has begun to cause a rashlike irritation in the collar area. I want to replace it, but I’m hesitating over buying another of the same type. Would I be better off with something synthetic like this nylon cord—or would that somehow be worse?

Any relevant experience or advice?

Tags as I wrote them: glasses, cords, lanyards, eyewear retainers, skin irritation.