Magnifiers aid those of us with presbyopia (diminished close vision that eventually affects EVERYONE). They can also be useful to read small print which is a feature of so many information leaflets. And some, like our BIG EYE magnifiers are just fun!
Kaleidoscopes which make patterns from small pieces inside the instrument are cousins of magnifiers but Londji's are in fact teleidoscopes that form kaleidoscopic patterns from objects around you.