CliC Ashbury Bifocal Reading Sunglasses +3.00 for Outdoor Reading

I am a woman & I have a smaller face frame. Grest that these are adjustable, but can only make larger, not smaller. Need the bifocal option, so was not given a size choice. Love the way they work though & will find a way to keep them on my nose!! Wish they made them to adjust a bit smaller too!! Trying to come up with a way to fix them to stay on nose. Anyone else had this problem? Suggestions on fixing? I tried to find a rubber nose piece to stick on so they wouldn't slip on my nose. No luck so far! Any suggestions for this welcome.