Meet the Spherics Family: A Tale of Big Hair & Hard Heads

(But, before you do, first print out the two attached sheets, rotate them 90 degrees, and put them side by side, faces up, big hair to the left.)

Here they are! The Spherics family. Ma is first in the first row, her four girls to the right. Pa and the five boys to the right of him. Large family. Ma with the biggest head of hair in her fashionable, Dutch cut. You see, the Spherics live in Holland, Huygens' home, and they are all related.
Now, as what happens sometimes in families, the relatives don't all like each other. Ma and Pa in Row1 think their kin in Row2 are too plastic, those in Row3 too glassy, and the Spherics in Row4, well, they're just too hard-headed to get along with. Of course, there's always the other side of the story too. The Spherics in Rows 2, 3, and 4 all think their kin in Row1 are too watery.
Despite all their differences, though, they are still one big family.
One thing they do all agree on is that they are much more orderly than that Aspherics family.

For those without printer access, here they all are again, ladies on the first page, gentlemen on the second. For those without any geometrical optics background at all, the faces in each row are of different media.
This should help some.