The Eye

Darwin once said that the very thought of the complexity of the eye gave him the chills.

The eye is constructed exactly like a camera except that it is infinitely more complex and sophisticated. Like some modern cameras, it has autofocus and automatic adjustment of the iris diaphragm. In the case of the eye, the lens actually changes it's shape or correction to focus at different distances. The lens is made of living cells that are marvelously transparent as is the cornea, the window like skin that covers the eye.

The most amazing component of the camera eye is it's "film" or retina. This light sensitive layer, which lines the back of the eye ball, is thinner than a sheet of Saran-Wrap and is vastly more sensitive to a wider range of light than any man made film. The best man-made film can handle a range of 1,000-to-one. By comparison, the human retina can handle a dynamic range of light of 10 billion-to-one and can sense as little as a single photon of light in the dark! In bright daylight, the retina bleaches out and turns it's "volume control" way down so as not to overload.

The light sensitive cells of the retina are like an extremely complex high gain amplifier. There are over 10 million such cells in the retina and they are packed together with a density of 200,000/mm{2} in the highly sensitive fovea. These photoreceptor cells have a very high rate of metabolism and must completely replace themselves about every 7 days! If you look at a very bright light such as the sun, they immediately burn out but are rapidly replaced in most cases. Because the retina is thinner than the wave length of visible light it is totally transparent. Each of these minute photoreceptor cells is vastly more complex than the most sophisticated man-made computer.

It has been estimated that 10 billion calculations occur every second in the retina before the light image even gets to the brain! It is sobering to compare this performance to the most powerful man-made computer. In an article published in the computer magazine Byte (April 1985) Dr. John Stevens said:

What makes this comparison even more incredible is the fact that nerve cells such as the photo cells of the retina conduct electrical signals approximately a million times slower than the circuit traces or "wires" in a man made supercomputer. Dr. Stevens said that if it were possible to build a single silicon chip that could simulate the retina using currently available technology it would have to weigh about 100 pounds where as the retina weighs less than a gram. The "super chip" would occupy 10,000 cubic inches of space whereas the retina occupies 0.0003 inches of space. The power consumption of the man-made superchip would be about 300 watts, whereas the retina consumes only 0.0001 watts of power!

Attempts to explain the evolution of the eye, like most other evolutionary "explanations," are merely untestable scenarios in the guise of science. Not only must one account for the eye itself but also an optically transparent "skin"' the cornea through the eye must look and a brain to process the optical information. The visual cortex of the brain, together with the eye, which is actually part of the brain, must translate optical information which begins as nothing more than differences in the amplitude and wave length of light rays into what is perceived as real time 3-dimensional color vision. There is undoubtedly a scientific explanation for all of this signal processing and we already know a great deal about it but we are no closer to a scientific explanation for how we came to have eyes in the first place. As radically different as invertebrates are from vertebrates in all of their organs, the invertebrate octopus has an eye strikingly similar to that of man! No wonder the Bible says "The hearing ear and the seeing eye the Lord hath made them all."