By: Dr. Jerry Bergman
One claim that is repeatedly printed in the scientific literature is that the human eye is backward, which is worse than poor design.
The reason for this claim is the light-sensing cells are in the back of the retina cells, requiring light to pass through layers of neurons and capillaries before it reaches the photosensitive part of the rods and cones.
Evolutionists explain the wiring of the human eye as a product of our unfortunate evolutionary baggage.
Oxford University Professor Richard Dawkins wrote that the most glaring example of imperfection in the human body is the retina: “Imagine a latter-day Helmholtz presented by an engineer with a digital camera, with its screen of tiny photocells, set up to capture images projected directly to the screen surface.
But now, suppose the eye’s ‘photocells’ are pointing backwards, away from the scene being looked at.
The ‘wires’ connecting the photocells to the brain run over all the surface of the retina, so the light rays have to pass through a carpet of wires before they hit the photocells. That design doesn’t make sense.”
He added: “One consequence of the photocells pointing backwards is that the wires which carry their data somehow have to pass through the retina and back to the brain. What they do, in the vertebrate eye, is converge on a particular hole in the retina, where they dive through it.
The hole is called the blind spot, because it is blind, but. … it is quite large, more like a blind patch ….. Once again, send it back to the designer.
It’s not just bad design, it’s the design of a complete idiot.” (From: Richard Dawkins. Greatest Show on Earth. 2010. pp. 353–355)
I reasoned that, as a creationist, there must be a good reason for this design. My evolutionary colleagues exclaimed, “Face it. Evolution is right, creation is wrong. There is no way to explain this idiotic design except by evolution.”
I did a lot of reading on this topic, even asking my eye doctor, Dr. Terra Richmond, for suggestions.
Intrigued, she spent some time reviewing her college ophthalmology textbooks and provided much insight to the problem, but still no good answer.
As I was then a graduate student at the Medical College of Ohio in Toledo, I took an independent study on the problem. The professor was intrigued with the problem as well, and together we combed the literature.
One part of the course that intrigued me was the microscopic analysis of the eye lens which looked like a large pile of flat glass plates.
This was after the programmed removal of nuclei and other light-scattering organelles from lens cells to achieve a high level of tissue transparency.
The eye lens consists of living cells which obtain nutrients from the surrounding fluids. The aqueous and vitreous humors contain nutrients that nourish and protect the eyes.
I eventually learned critical reasons for the retina’s reverse design. One is the fact that it allows the rods and cones to connect with the retinal pigment epithelial cells that provide nutrients to the retina, recycle photopigments, and provide an opaque layer to absorb excessive light. The pigment epithelial cells thus connect directly with the blood supply required to maintain their life.
Furthermore, the pigment epithelium tissue performs numerous other functions that are critical for retina viability and activity.
One is that it phagocytizes ten percent of the mass of each photoreceptor outer segment on a diurnal schedule, and constantly restores the chromophore to the 11-cis-retinal form from its all-trans configuration, permitting visual pigment synthesis and regeneration.
Still other reasons, not mentioned here, could be provided to document why this design is actually required for vision to exist.
Even the blind spot that Dawkins claimed is “quite large, more like a blind patch” in fact takes up less than one percent of the retinal surface.
We are not normally aware of it because the brain fills in the missing information which it obtains from the other eye.
I eventually published my findings in a peer-reviewed scientific journal. The article was titled, “Is the Inverted Human Eye a Poor Design?” and was published in Journal of the American Scientific Affiliation 52(1):18-30, March 2000.
The view that the backward-retina design is required for vision is now widely accepted in the scientific community, and I would like to believe that my work made a small contribution to solving the problem.
One recent article in the journal Current Biology on the history of the issue, gave many reasons why the vertebrate-eye design is a sterling example of excellent design. This design produced the eyes of the eagle that allow it to see a mouse two miles (3.2 kilometers) away.
For comparison, a human with excellent vision may be able to see the same animal less than one city-block (0.3 kilometers) away.
Ironically, the Current Biology article listed the human inverted eye as an example of the amazing ability of evolution (not God) to design things.
Dr. Bergman is a multi-award-winning teacher and author. He has taught in the science and psychology area for over 40 years at the University of Toledo Medical College, Bowling Green State University, and other colleges. His 9 degrees include a Doctorate from Wayne State University in Detroit, Michigan. He has over 1,800 publications in both scholarly and popular science journals that have been translated into 13 languages. His publications are in over 2,400 college libraries in 65 countries. Bergman has spoken over 2,000 times at colleges and churches in America, Canada, Europe, the South Sea Islands, and Africa.