If an eyeglass lens falls out of the frames on Shabbos. Can the lens be put back into the frame? Can the lens and/or frame be put away in a safe place so that it does not get damaged or lost?
The lens may not be replaced as this would violate creating/fixing a ‘kli’ [vessel/object] on Shabbos. If the frame can readily be replaced [i.e. it’s not broken] then there is a prohibition of muktzeh, as we are concerned handling it may lead to fixing it. If it is on the floor it may be kicked aside with your foot to a safer place.
See Shulchan Aruch O:C 308:16.