The eye's retina is located in the back of the eye and is responsible for receiving the focused light and generating signals to send to the brain. The rods and cones are packed side by side and have their nerve endings exiting out the front of the retina. These individual nerves are then routed to a central location where nerves exit out the back of the eye forming the optical nerve, a thick cord which carries the signals to the brain. (that's where your blind spot is). This means the light has to pass through this web of nerves before it reaches the light sensing rods and cones. Well the evolutionists say this represents a bad design and point to this as evidence for their theory since no good creator would ever use such a poor design. Such a creator would obviously turn the rods and cones around so that the nerve endings exited through the rear of the eye. This way, the light would not have any interference in reaching the light sensitive cells.
But is it really bad design? Turns out, the rods and cones are attached to the Retinal Pigment Epithelium (RPE), a blood engorged membrane which is responsible for delivering nutrients to the rods and cones. What benefits are their to having the rods attached in a reverse orientation to the RPE?
- The light sensitive end of the rod which is closest to to the RPE at the rear has a huge demand for nutrients since these cells are so active. Furthermore, their is much damage to these cells from the light which strikes them. Have you ever noticed how a car's paint begins to fade and peel if left outside in the sun for long periods of time? It is the energetic rays of the sun which does this damage. Same thing with the eye. So not only do these cells need nutrients to supply the energy needed for their activity, but also for the constant rebuilding necessary due to damage. The rods are place in an inverted position so that the most needed area of the cell is closed to the blood supply.
- Also you know how light can warm things up, even your skin can get hot and needs to sweat to carry away the excess heat build up. Same thing again with the rods of the eye which are cooled by the blood flow away from the RPE which acts as a radiator.
- Finally, the RPE is very dark in color. If it were to be placed on the inside of the eye in front of the rods so the they could be turned in the "right" direction, no light could pass through at all since the RPE is opaque. This dark color at the back of the eye serves a good purpose too. It acts as a light absorber so that no stray photons of light bounce around like they would off a lighter surface. Our camera lenses are all painted flat black on the inside surfaces to accomplish the same thing.
So it turns out that this is not such a bad design after all. In fact the so called "good design" the scientists argue for would indeed be a very poor design. Of course the final point is that this so called "bad design" works marvelously well!
We are indeed fearfully and wonderfully made, and that we should know very well. [Psalm 139]