In the beginning of Avengers: Infinity War Tony Stark's glasses suddenly vanished.
Were they made of nano particles which dissolved and became part of his suit?
If you pay close attention to the scene the glasses are in Stark's hand as he pulls them from his face and as his arm lowers the glasses disappear.
They are not dropped or put away so we must assume that they are also nano-particle based and are subsumed into his suit.
It's difficult to show this as it's a very quick shot with barely a split-second between the two images but...
Glasses in hand
Stark's glasses didn't vanish. He put them away.
In the opening scene we see that he tightens up his regular clothes which will act as intermediate layer between his armour and skin later on. Then he starts walking towards Maw. In that moment, we can see Stark remove his glasses while the nano suit is still covering him. Before the suit coverage is complete, we can see Stark put away the glasses that he removed from his face moments ago.
There was no any other indication about the materials that glasses were made of, their primary goal is to comunicate with Friday and act as a HUD when needed.
I couldn't find a better quality source on YouTube at the moment, this clip is not a good quality one, apologies for that.