My very first pair of Juliets eventually had their nosebridge loosened up quite a bit after 5 years of using them with the size 25 temple shocks. I took them in to my local Oakley optometrist and had them send it back in for a tune up. Came back practically the same, still loose. Went back in again, came back a second time a wee bit better, and was told it was the best they could do. If you want it to be tight enough to not move at all, then don't expect the tune up to solve that problem...you'd just need to buy a brand new pair. Since then, with all new Juliets I've bought, I've stuck to using the size 15 temple shocks, so that the frame doesn't have to stretch as much around my head. And that's really what you have to do if you want to preserve the frame's tightness.