Most certainly. If you have one lens per topic (or even several lenses to cover the one topic) is the way to go. Don't go off topic. You'll only confuse the reader.
If you do have multiple lenses about a single topic, linking them together will really help with their ranking in search engines.
There are many ways to do this, with varying degrees of ease: Use the 'Lensroll' feature in the side bar of the lens Add your other lenses to the 'Discovery Tool' (edit the Intro module to find this) Add a 'Link List' module to your lens Add the 'Featured Lenses' module (looks prettier) Use HTML Code to manually link to your other lenses