Blitz the blueberry and lime juice with 75ml cold water in a blender until smooth.
Fill a 10-hole-lollipop mould with the blueberry mixture. If your mould has a stick holder, add the sticks now. Otherwise, transfer the mould to the freezer, then remove after 20 minutes and add the sticks then. Leave to completely freeze overnight.
When ready to eat, remove the ice lollies from the freezer and serve. If they are hard to get out, very briefly run under hot water to loosen.