Like all biological structures, explaining the vertebrate eye—or any eye for that matter—is a challenge to neo-Darwinism (modern synthesis). When conventional scientists attempt to describe eye evolution, they begin with a simple or “primitive” visual system and extrapolate, vaguely gesturing to mystical evolution by natural selection, to explain the highly sophisticated vertebrate eye.

Major parts of the evolutionary progression seen in animals, from nondirectional photoreception to high-resolution vision, is mirrored within the single cells of phytoplankton. In both animals and phytoplankton, selection on the photoreceptive systems acts primarily on the fitness of the behavior, and this in turn causes selection on the performance of the sensory systems.¹

But selection and fitness do not explain the origin of such irreducible visual systems.^2,3 These complex photosensor systems could only have been specifically designed for organisms according to their needs. Even “simple” eyespots (pigment spot ocelli) are shockingly advanced in single-celled creatures.⁴

Eyespots of astonishingly advanced organization appear even in some unicellular forms. That of the dinoflagellate, Nematodinium, bears a lens, a light-gathering chamber, and a photoreceptive pigment cup—all developed within a single-celled organism.⁵

Despite the difficulties evolutionists face to explain the origin of eyes, four scientists recently decided to try again, publishing an article about the alleged evolution of the vertebrate retina. They began by stating that the “retina is a uniquely complex and evolutionarily conserved structure.”⁶ There’s no question as to the retina’s intricacy, and calling it “conserved” means that it has remained relatively unchanged over supposedly millions of years. In other words, the retina is unevolved.

However, the authors proposed that “a composite ancestral median eye” from an unknown one-eyed sea creature was repurposed, eventually becoming the vertebrate retina over time.⁶ Furthermore, the remnants of this cryptic median eye somehow became the pineal endocrine gland (epiphysis cerebri) in our brains.

So, the paired eyes of people (and other vertebrates) serendipitously originate from a 600-million-year-old microscopic, single-celled, cyclopean ancestor with a visual organelle that also remains operative in today’s phytoplanktonic descendants.

Additionally, according to the researchers’ explanation, this ancestor once again began to lead an active aquatic life, resulting in a need for paired eyes. Therefore, a second eye began to evolve, replicating the original small median eye. This is all purely theoretical, if not speculative.

Dan-Eric Nilsson, professor emeritus in sensory biology at Lund University in Sweden, shared one of his takeaways:

Now we finally understand why the paired eyes of vertebrates differ so radically from the eyes of all other animal groups, such as insects and squid. The film of our eyes—the retina—developed from the brain, whereas the eyes of insects and squid originate in the skin on the sides of the head.⁷

Vertebrates have always been obviously different from insects and squid. It is not surprising therefore, that their eyes form differently. But this most recent story does not provide sufficient scientific evidence to indicate they evolved. What we observe better fits the record of eye origins in Genesis: the invertebrate and vertebrate eyes were purposefully created and uniquely formed. They have always had distinct functionality.

To conclude, the evolution of visual systems is merely subjective and speculative. Nilsson and his colleague Colley are among many who resort to reconstructing “a plausible set of evolutionary events and causes leading to the unique condition in vertebrates.”¹ No one has observed these events and causes. It must be taken by faith.

Conversely, faith in the Creator is not only justified and supported by what is seen in creation,⁸ but it can also bring salvation and eternal life: “For by grace you have been saved through faith, and that not of yourselves; it is the gift of God.”⁹

References

1. Colley, N. and D. Nilsson. 2016. Photoreception in Phytoplankton. Integrative and Comparative Biology. 56 (5): 764–775. 
2. Guliuzza, R. 2011. Darwin’s Sacred Imposter: How Natural Selection Is Given Credit for Design in Nature. Acts & Facts. 40 (7): 12–15. 
3. Guliuzza, R. 2011. Darwin’s Sacred Imposter: The Illusion That Natural Selection Operates on Organisms. Acts & Facts. 40 (9): 12–15.
4. Sherwin, F. 2017. Do ‘Simple’ Eyes Reflect Evolution? Acts & Facts. 46 (9): 20. 
5. Hickman, C. et al. 2024. Integrated Principles of Zoology, 19th ed. New York: McGraw Hill, 754.
6. Kafetzis, G. et al. 2026. Evolution of the Vertebrate Retina by Repurposing of a Composite Ancestral Median Eye. Current Biology. 36 (4): 153–170.
7. Lund University. How a One-Eyed Creature Gave Rise to Our Modern Eyes. Phys.org. Posted on phys.org February 25, 2026.
8. Hebrews 11:3; Romans 1:20.
9. Ephesians 2:8.

* Dr. Sherwin is a science news writer at the Institute for Creation Research. He earned an M.A. in invertebrate zoology from the University of Northern Colorado and received an honorary doctorate of science from Pensacola Christian College.