The human Eye Rods and Cones Design- Backwards ?

The human Eye Rods and Cones Design- Backwards ?

Rods have a protein called rhodopsin and cones have photopsins, these are stuck in the back of the retina. That means that the light is absorbed closer to the outside of the eye. Someone may ask: Aren't these set up backwards? What is going on here?

The "backwards" organization of rods and cones is helpful for a few different reasons.

Image courtesy of : (Dr. Biology, 2010).

Cell orientation makes it easier to recycle parts.

Image courtesy of: (Dr. Biology, 2010).

First of all, the discs containing rhodopsin or photopsin are constantly recycled to keep your visual system healthy. By having the discs right next to the epithelial cells (retinal pigmented epithelium: RPE) at the back of the eye, parts of the old discs can be carried away by cells in the RPE.

Another benefit to this layout is that the RPE can absorb scattered light. This means that your vision is a lot clearer. Light can also have damaging effects, so this set up also helps protect your rods and cones from unnecessary damage.

While there are many other reasons having the discs close to the RPE is helpful, we will only mention one more. Think about someone who is running a marathon. In order to keep muscles in the body working, the runner needs to eat special nutrients or molecules during the race. Rods and cones are similar, but instead of running, they are constantly sending signals. This requires the movement of lots of molecules, which they need to replenish to keep working. Because the RPE is right next to the discs, it can easily help reload photoreceptor cells and discs with the molecules they need to keep sending signals.

(Dr. Biology, 2010).

Rods and Cones of the Human Eye https://askabiologist.asu.edu/rods-and-cones

Why Dawkins does not know physics, biology, chemistry and electro-mechanical feedback design

In 1986, Richard Dawkins published The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design. In it, Dawkins used the vertebrate eye as evidence against design:

“Any engineer would naturally assume that the photocells would point towards the light, with their wires leading backwards towards the brain. He would laugh at any suggestion that the photocells might point away from the light, with their wires departing on the side nearest the light. Yet this is exactly what happens in all vertebrate retinas. Each photocell is, in effect, wired in backwards, with its wire sticking out on the side nearest the light. The wire has to travel over the surface of the retina, to a point where it dives through a hole in the retina (the so-called “blind spot”) to join the optic nerve.” (Wells, 2018).

Yet, what he does not know is that the position of the rods and cones in our human eyes are there for a good and well deserved reason:

According to Arizona State University, “ask a biologist” web site:

“The "backwards" organization of rods and cones is helpful for a few different reasons.”

“First of all, the discs containing rhodopsin or photopsin are constantly recycled to keep your visual system healthy. By having the discs right next to the epithelial cells (retinal pigmented epithelium: RPE) at the back of the eye, parts of the old discs can be carried away by cells in the RPE.”

(Dr. Biology, 2010).

“Another benefit to this layout is that the RPE can absorb scattered light. This means that your vision is a lot clearer. Light can also have damaging effects, so this set up also helps protect your rods and cones from unnecessary damage.” (Dr. Biology, 2010).

And not only that, but there are many more reasons. Arizona State University web site “ask a biologist” continues:

“While there are many other reasons having the discs close to the RPE is helpful, we will only mention one more. Think about someone who is running a marathon. In order to keep muscles in the body working, the runner needs to eat special nutrients or molecules during the race. Rods and cones are similar, but instead of running, they are constantly sending signals. This requires the movement of lots of molecules, which they need to replenish to keep working. Because the RPE is right next to the discs, it can easily help reload photoreceptor cells and discs with the molecules they need to keep sending signals.”

(Dr. Biology, 2010).

https://askabiologist.asu.edu/rods-and-cones

Obviously, Dawkins, has very poor knowledge of biology and or engineering design. Evolutionists like him have not idea what how perfectly designed the eye is. Evolutionists like Douglas Futuyma, Kenneth R. Miller, George Williams Kenneth Mason, Nathan Lents, Jonathan Losos, and Susan Singer, all fall into this category, obviously. (Wells, 2018)

Oh, how wrong was Lents when he said:

“there are no working hypotheses about why the vertebrate retina is wired in backwards. It seems to have been a random development that then ‘stuck’ because a correction of that magnitude would be very difficult to pull off with random mutations…. During the evolution of the cephalopod eye, the retina took shape in a more logical way, with the photoreceptors facing outward toward the light. Vertebrates were not so lucky.” (wells, 2018).

Arizona State University, “ask a biologist” web site made it perfectly clear: “The "backwards" organization of rods and cones is helpful for a few different reasons.” (Dr. Biology, 2010).

Additionally, Wells makes it perfectly clear the reason for rods and cones disks being situated at the back of the retina:

“The light-sensing cells in a vertebrate retina require lots of nutrients and vast amounts of energy.

In mammals, they have the highest metabolic rate of any tissue in the body. About three-quarters of the blood supply to the eye flows through a dense network of capillaries called the “choriocapillaris,” which is situated behind the retina (e in the drawing). Oxygen and nutrients are transported from the choriocapillaris to the light-sensing cells by an intermediate layer of cells called the “retinal pigment epithelium” (RPE, d in the drawing).” (Wells, 2018).

Thus, the reason why rods and cones are situated where they are. Divine design wins over human imagination.

References

Dr. Biology. (2010). Rods and Cones of the Human Eye. Publisher: Arizona State University School of Life Sciences Ask A Biologist. Retrieved from https://askabiologist.asu.edu/rods-and-cones

Wells, J. (2018). Is the Human Eye Really Evidence Against Intelligent Design? Evolution News. Retrieved from https://evolutionnews.org/2018/04/is-the-human-eye-really-evidence-against-intelligent-design/

Copyright

Fred Echeverria

Hawaii On Line University