Yet ekmetts package is called "lens" and not "optic". While I agree with you in principle, I think that ship has sailed and for all practical purposes, "lenses

Yet ekmetts package is called "lens" and not "optic". While I agree with you in principle, I think that ship has sailed and for all practical purposes, "lenses" has come to mean both the narrower definition that is arguably correct, and optics more generally. It's a historical accident, much like a lot of people use "function" to mean all sorts of subprogram, including procedures and sometimes even methods!