There are two ways to appear invisible. First, you can actually be — well — invisible. I’ve never actually seen anything like that.
(Well, of course I haven’t.)
Or, you can be so small and inconspicuous as to escape notice, and thus avoid scrutiny.
With a lens of the macro variety, we photographers are able to overcome the limitations of our eyes and delve into the world of the inconspicuously small. Often, the image captured from our macro-mounted camera setup will reveal details we never even glimpsed in the viewfinder.