# center the eyeball on the base
overlay(circle(15, "solid", "blue"),
  circle(30, "solid", "tan"))

# position the eyeball lower and left on the base
overlay-xy(circle(15, "solid", "blue"),
  -25, -25,
  circle(30, "solid", "tan"))

# we have our left-eye image -- let's name it
left-eye = overlay-xy(circle(15, "solid", "blue"),
                   -25, -25,
                   circle(30, "solid", "tan"))

# put two eyes together
beside(left-eye, left-eye)

# leverage symmetry to avoid writing second eye from scratch
beside(left-eye, flip-horizontal(left-eye))