The Helix Nebula from La Silla Observatory. (WFI, MPG/ESO 2.2-m Telescope, La Silla Obs., ESO)
View ports from parallel universes.
Eyes are orbs…the shape of orbs is spherical, and, is governed by physics. Take a super nova star, explode it in all directions, you end up with a formation of dust and gas that has a spherical body.
And that is where the similarity between eyeballs and some nebulae ends. I say some because, unlike super novae nebulae, a gravitational nebula is the result of particles and gases coming together due to mass doing its thing. They form in random shapes as a result of varied densities and gravitational fields of differing forces that tug gases and particles one way or the other. Made all the more non-spherical when enough mass does happen to come together to form a star. Which, simultaneously draws in matter while pushing other matter further from its center. Get enough stars forming, you end up with ripples of matter overlapping across a very large region. See the Pillars of Creation as example.