We sleep with the bedroom window open and if there is any breeze outside the curtain rings rattle on the curtain pole. Any ideas how I could stop this apart from the obvious of closing the window.
Metal against metal can be noisy and distracting.
One simple HACK would be to put a thin strip of plastic electrical tape along the top of the curtain rod. Try to position it so it does not show when the rod is in position for use.
The plastic tape will provide a smooth layer for the eyelets to slide over yet enough to insulate the metal parts from making noise where they may touch.
Total time for application: 15 - 20 minutes.
Stand on something stable when reaching to position your curtains.