My contact lens solution comes in a 250 ml bottle. The irritating rules for carry-on liquids allow passengers to take a 1 litre bag full of liquids - so in theory I could take four regular bottles. The catch is that liquid containers must be 100 ml or less, and the bag must be 20 cm x 20 cm or less.
This pack comes with two 60 ml bottles of ReNu and a bag of the regulation size plus two spare lens cases. You are allowed to take both bottles on board.
I had difficulty finding the exact same pack in the high street so well done to Bausch & Lomb for coming up with the pack, and to Amazon for stocking them!