I'm making a magnifying glass from scratch. What's the mathematically ideal shape?

As the ultimate test of my lapidary skill, I've decided to make a functional aspheric magnifying glass.

radius=27mm thickness=7mm

Instead of the typical spherical convex lens faces, I'd like to try for something mathematically pleasing. I'm reading that the ideal lens (one which focuses parallel light to a "perfect" focal point) will have one face elliptical and one hyperbolic--is this correct? And if so, what ellipse and hyperbola would work for me in this case?

I plan to 3D print the inverted surfaces and use those as an indicator of where I need to take off more material. The end result will not be perfect, but I'm okay with that. Any help/guidance is much appreciated!