I think I just designed a new tool, an invention, if you will. My base subject is the magnifying glass. As we know magnifying lens, refocuses light as it travels through, or is observed through, its polished convex surface planes.
Now suppose those surface planes were made of, semi-flexible transparent bladders. Connected to those transparent bladders would be a handle, much like a large syringe.
The syringe is filled with clear oil. As the plunger injects the oil into the space between the two bladders, whey bow outward, changing the focal plane.
I even have a name for this product.
Zoom-nifying Lens 
