(Which allegedly required no actual design) With references, courtesy Philip Cunningham:
The human eye consists of over two million working parts making it second only to the brain in complexity (1).
The retina covers less than a square inch, and contains 137 million light-sensitive receptor cells. The retina possesses 7 million cones, which provide color information and sharpness of images, and 120 million rods which are extremely sensitive detectors of white light (2).
There are between seven to ten-million shades of color the human eye can detect (3).
The rod can detect a single photon. Any man-made detector would need to be cooled and isolated from noise to behave the same way (4).
On average, about a quarter of a billion photons enter our eyes each second (5).
For visible light, the energy carried by a single photon would be around a tiny 4 x 10-19 Joules; this energy is just sufficient to excite a single molecule in a photoreceptor cell of an eye (6).
The eye is so sensitive that it can, under normal circumstances, detect a candle 1.6 miles away (7),
But if you’re sitting on a mountain top on a clear, moonless night you can see a match struck 50 miles away (8).
It only takes a few trillionths of a second, (picoseconds), for the retina to absorb a photon in the visible range of the spectrum (9).
The inverted retina, far from being badly designed, is a design feature, not a design constraint. Müller cells in the ‘backwards’ retina span the thickness of the retina and act as living fiber optic cables to shepherd photons through to separate receivers, much like coins through a change sorting machine (10).
The eye is infinitely more complex than any man-made camera (11).
The eye can handle between 500,000 and 1.5 million messages simultaneously, and gathers 80% of all the knowledge absorbed by the brain (12).
The brain receives millions of simultaneous reports from the eyes. When its designated wavelength of light is present, each rod or cone triggers an electrical response to the brain, which then absorbs a composite set of yes-or-no messages from all the rods and cones (13).
There is a biological computer in the retina which compresses, and enhances the edges, of the information from all those millions of light sensitive cells before sending it to the visual cortex where the complex stream of information is then decompressed (14).
This data compression process has been referred to as “the best compression algorithm around,” (15 & 15a).
While today’s digital hardware is extremely impressive, it is clear that the human retina’s real-time performance goes unchallenged. To actually simulate 10 milliseconds of the complete processing of even a single nerve cell from the retina would require the solution of about 500 simultaneous nonlinear differential equations 100 times and would take at least several minutes of processing time on a Cray supercomputer. Keeping in mind that there are 10 million or more such cells interacting with each other in complex ways, it would take a minimum of 100 years of Cray time to simulate what takes place in your eye many times every second (16). (of note: the preceding comparison was made in 1985 when Cray supercomputers ruled the supercomputing world).
In an average day, the eye moves about 100,000 times, and our mind seems to prepare for our eye movements before they occur (17).
In terms of strength and endurance, eyes muscles are simply amazing. You’d have to walk 50 miles to give your legs the same workout as the muscles in one of your eyes get in a day (18).
The brain exploits a feedback system which produces phenomenally precise eye movements (19).
The human is the only species known to shed tears when they are sad (20).
Tears are not just saline. Tears have a similar structure to saliva and contain enzymes, lipids, metabolites and electrolytes (21).
And, tears contain a potent microbe-killer (lysozyme) which guards the eyes against bacterial infection (22).
The average eye blinks one to two times each minute for infants and ten times faster for adults.
This blinking adds up to nearly 500 million blinks over an average lifetime (23).
References:
- – 20 Facts About the Amazing Eye – 2014
- An eye is composed of more than 2 million working parts…. 20: Eyes are the second most complex organ after the brain. – Susan DeRemer, CFRE – Discovery Eye Foundation
- Vision and Light-Induced Molecular Changes
Excerpt : “The retina is lined with many millions of photoreceptor cells that consist of two types: 7 million cones provide color information and sharpness of images, and 120 million rods (Figure 3) are extremely sensitive detectors of white light to provide night vision.” – Rachel Casiday and Regina Frey Department of Chemistry, Washington University
- – Number of Colors Distinguishable by the Human Eye – 2006 “Experts estimate that we can distinguish perhaps as many as 10 million colors.” – Wyszecki, Gunter. Color. Chicago: World Book Inc, 2006: 824…. “Our difference threshold for colors is so low that we can discriminate some 7 million different color variations (Geldard, 1972).” – Myers, David G. Psychology. Michigan: Worth Publishers, 1995: 165. From Number of Colors Distinguishable by the Human Eye
- Study suggests humans can detect even the smallest units of light – July 21, 2016
Excerpt: Research,, has shown that humans can detect the presence of a single photon, the smallest measurable unit of light. Previous studies had established that human subjects acclimated to the dark were capable only of reporting flashes of five to seven photons…
it is remarkable: a photon, the smallest physical entity with quantum properties of which light consists, is interacting with a biological system consisting of billions of cells, all in a warm and wet environment,” says Vaziri. “The response that the photon generates survives all the way to the level of our awareness despite the ubiquitous background noise. Any man-made detector would need to be cooled and isolated from noise to behave the same way.”…
The gathered data from more than 30,000 trials demonstrated that humans can indeed detect a single photon incident on their eye with a probability significantly above chance.
“What we want to know next is how does a biological system achieve such sensitivity? How does it achieve this in the presence of noise?
- How many photons get into your eyes? – 2016
Excerpt : About half a billion photons reach the cornea of the eye every second, of which about half are absorbed by the ocular medium. The radiant flux that reaches the retina is therefore approx. 2*10^8 photons/s.
- Photon Excerpt For visible light the energy carried by a single photon is around a tiny 4×10–19 joules; this energy is just sufficient to excite a single molecule in a photoreceptor cell of an eye, thus contributing to vision.[4]
- How Far Can We See and Why? Excerpt: “Detecting a candle flame: Researchers believe that without obstructions, a person with healthy but average vision could see a candle flame from as far as 1.6 miles.”
- An Eye for Exercise Your eye is a very active organ – December 28, 2001
(HealthDayNews) — The cells in the retina are so sensitive that if you’re sitting on a mountain top on a clear, moonless night you can see a match struck 50 miles away.
- Vision and Light-Induced Molecular Changes
Excerpt: “Thus, when 11-cis-retinal absorbs a photon in the visible range of the spectrum, free rotation about the bond between carbon atom 11 and carbon atom 12 can occur and the all-trans-retinal can form. This isomerization occurs in a few picoseconds (10-12 s) or less.” – Rachel Casiday and Regina Frey, Department of Chemistry, Washington University
- Fiber optic light pipes in the retina do much more than simple image transfer – Jul 21, 2014
Excerpt: Having the photoreceptors at the back of the retina is not a design constraint, it is a design feature. The idea that the vertebrate eye, like a traditional front-illuminated camera, might have been improved somehow if it had only been able to orient its wiring behind the photoreceptor layer, like a cephalopod, is folly. Indeed in simply engineered systems, like CMOS or CCD image sensors, a back-illuminated design manufactured by flipping the silicon wafer and thinning it so that light hits the photocathode without having to navigate the wiring layer can improve photon capture across a wide wavelength band. But real eyes are much more crafty than that.
A case in point are the Müller glia cells that span the thickness of the retina. These high refractive index cells spread an absorptive canopy across the retinal surface and then shepherd photons through a low-scattering cytoplasm to separate receivers, much like coins through a change sorting machine. A new paper in Nature Communications describes how these wavelength-dependent wave-guides can shuttle green-red light to cones while passing the blue-purples to adjacent rods. The idea that these Müller cells act as living fiber optic cables has been floated previously. It has even been convincingly demonstrated using a dual beam laser trap….
…In the retina, and indeed the larger light organ that is the eye, there is much more going on than just photons striking rhodopsin photopigments. As far as absorbers, there are all kinds of things going on in there—various carontenoids, lipofuscins and lipochromes, even cytochrome oxidases in mitochondria that get involved at the longer wavelegnths….
,,In considering not just the classical photoreceptors but the entire retina itself as a light-harvesting engine… that can completely refigure (its) fine structure within a few minutes to handle changing light levels, every synapse appears as an essential machine that percolates information as if at the Brownian scale, or even below….
- The Wonder of Sight – April 15, 2020
Excerpt: The eye processes approximately 80% of the information received from the outside world. In fact, the eyes can handle 500,000 messages simultaneously. It happens all the time, and you don’t even have to think about it. Your eyes just do it! The eye is infinitely more complex than any man-made camera or telescope.
- Walk By Faith – Now See Here, Touch & Smell to Discern Good & Evil – July 6, 2018
Excerpt: “I Am Joe’s Eye” (from the Reader’s Digest series) says “For concentrated complexities, no other organ in Joe’s body can equal me … I have tens of millions of electrical connections and can handle 1.5 million simultaneous messages. I gather 80 percent of all the knowledge Joe absorbs.”
- Fearfully and Wonderfully Made – Philip Yancey, Paul Brand
Excerpt: The brain receives millions of simultaneous reports from the eyes. When its designated wavelength of light is present, each rod or cone triggers an electrical response to the brain, which then absorbs a composite set of yes-or-no messages from all the rods and cones.
- Retina – Spatial encoding
Excerpt: When the retina sends neural impulses representing an image to the brain, it spatially encodes (compresses) those impulses to fit the limited capacity of the optic nerve. Compression is necessary because there are 100 times more photoreceptor cells than ganglion cells. This is done by “decorrelation”, which is carried out by the “centre–surround structures”, which are implemented by the bipolar and ganglion cells.
There are two types of centre–surround structures in the retina – on-centres and off-centres. On-centres have a positively weighted centre and a negatively weighted surround. Off-centres are just the opposite. Positive weighting is more commonly known as excitatory, and negative weighting as inhibitory.
These centre–surround structures are not physical apparent, in the sense that one cannot see them by staining samples of tissue and examining the retina’s anatomy. The centre–surround structures are logical (i.e., mathematically abstract) in the sense that they depend on the connection strengths between bipolar and ganglion cells. It is believed that the connection strength between cells is caused by the number and types of ion channels embedded in the synapses between the bipolar and ganglion cells.
The centre–surround structures are mathematically equivalent to the edge detection algorithms used by computer programmers to extract or enhance the edges in a digital photograph. Thus, the retina performs operations on the image-representing impulses to enhance the edges of objects within its visual field.
- JPEG for the mind: How the brain compresses visual information – February 11, 2011
Excerpt “Computers can beat us at math and chess,” said Connor, “but they can’t match our ability to distinguish, recognize, understand, remember, and manipulate the objects that make up our world.” This core human ability depends in part on condensing visual information to a tractable level. For now, at least, the brain format seems to be the best compression algorithm around.
15a. Optimised Hardware Compression, The Eyes Have It. – 2011
- Can Evolution Produce an Eye? Not a Chance! by Dr. David Menton on August 19, 2017
Excerpt: In an article in Byte magazine (April 1985), John Stevens compares the signal processing ability of the cells in the retina with that of the most sophisticated computer designed by man, the Cray supercomputer:
“While today’s digital hardware is extremely impressive, it is clear that the human retina’s real time performance goes unchallenged. Actually, to simulate 10 milliseconds (one hundredth of a second) of the complete processing of even a single nerve cell from the retina would require the solution of about 500 simultaneous nonlinear differential equations 100 times and would take at least several minutes of processing time on a Cray supercomputer. Keeping in mind that there are 10 million or more such cells interacting with each other in complex ways, it would take a minimum of 100 years of Cray time to simulate what takes place in your eye many times every second.”
- Looking At What The Eyes See – February 25, 2011
Excerpt: We move our eyes three times a second, over 100,000 times each day. Why isn’t life blurrier? Reporting in Nature Neuroscience, psychologist Martin Rolfs and colleagues found that our mind seems to prepare for our eye movements before they occur, helping us keep track of objects in the visual field.
- An Eye for Exercise Your eye is a very active organ – December 28, 2001 (HealthDayNews) — Did you know that you’d have to walk 50 miles to give your legs the same workout as the muscles in one of your eyes get in a day?
- How do our eyes move in perfect synchrony? By Benjamin Plackett – June 21, 2020
Excerpt: “You have a spare one in case you have an accident, and the second reason is depth perception, which we evolved to help us hunt,” said Dr. David Guyton, professor of ophthalmology at The Johns Hopkins University. But having two eyes would lead to double vision if they didn’t move together in perfect synchrony. So how does the body ensure our eyes always work together?
To prevent double vision, the brain exploits a feedback system, which it uses to finely tune the lengths of the muscles controlling the eyes. This produces phenomenally precise eye movements, Guyton said.
Each eye has six muscles regulating its movement in different directions, and each one of those muscles must be triggered simultaneously in both eyes for them to move in unison, according to a 2005 review in the Canadian Medical Association Journal. “It’s actually quite amazing when you think about it,” Guyton told Live Science. “The brain has a neurological system that is fantastically organized because the brain learns over time how much stimulation to send to each of the 12 muscles for every desired direction of gaze.”
- Why Only Humans Shed Emotional Tears – 2018
Abstract Producing emotional tears is a universal and uniquely human behavior…
- Facts About Tears – Dec. 21, 2018 Excerpt Tears Have Layers
Tears are not just saline. They have a similar structure to saliva and contain enzymes, lipids, metabolites and electrolytes. Each tear has three layers:
An inner mucus layer that keeps the whole tear fastened to the eye.
A watery middle layer (the thickest layer) to keep the eye hydrated, repel bacteria and protect the cornea.
An outer oily layer to keep the surface of the tear smooth for the eye to see through, and to prevent the other layers from evaporating.
Lacrimal glands above each eye produce your tears…
- How Tears Go ‘Pac-Man’ To Beat Bacteria – January 20, 2012
Excerpt: In 1922, a few years before he won the Nobel Prize for his discovery of penicillin, bacteriologist Alexander Fleming discovered in human tears a germ-fighting enzyme which he named lysozyme. He collected and crystallized lysozyme from his own tears, then wowed contemporaries at Britain’s Royal Society by demonstrating its miraculous power to dissolve bacteria before their very eyes.
“That’s a seriously bodacious experiment”…
- Eyelids—Intermittent Wipers – Dr. Don DeYoung – October 20, 2013
Excerpt: The blinking of our eyes is automatic and essential. Its saline washer fluid moistens and protects the outer cornea of the eye while removing dust. Other protective features include our eyebrow “umbrellas” and recessed eyeball sockets.
The average eye blinks one to two times each minute for infants and ten times faster for adults. This blinking adds up to nearly 500 million blinks over an average lifetime. The actual mechanism, however, is not well understood. It may involve a “blinking center” in the brain.
Today billions of windshield wipers duplicate the eye’s intermittent blinking. Yet none last as long or work as efficiently as our God-given eyelids.