What keeps contact lenses on your eyes

Matt: Is it really possible for contact lenses to slide around to the back of your eye and get lost somewhere in your head forever? My mother tells me this is true. She says it happened to a friend of hers. — Worried, La Mesa

From festive stuff to goofy stuff. We’re off to a good start here at Queries Central this year. Did Mom notice that while her friend’s lens was siding around her brain, she was thinking much more clearly? Maybe there’s an up side to this. Personally, I have visions of our lenses migrating to the backs of our eyes, klinking down into our sinus cavities, and rattling around there until we blow our noses and they pop out again. No, no, Worried. Our eyes are designed with little lens-catchers, called conjunctiva, which are attached around our eyeballs and fold forward to create the lining for our upper and lower eyelids. So a lens can seem to be lost forever, but under normal circumstances it can’t disappear into your head or set up some kind of equatorial orbit around your eyeball.