How many pixels is the image taken by human retina?

We know that everyone has a pair of eyes and everyone is using them. But how do eyes see things? Physiology tells us that human vision is accomplished by the simultaneous activities of eyes, optic nerve and visual center. The eye is the peripheral organ of vision, and it is a special sense with light waves as suitable stimulation. The light emitted by external objects refracts through the transparent tissue of the eye and forms an image on the fundus retina; After the retina is stimulated by light, it causes a series of physical and chemical changes of visual cells, resulting in a potential change called receptor potential. Through the transmission of bipolar cells, the ganglion cells can generate pulse signals, and the light energy can be converted into nerve impulses, and then the pulse is transmitted to the visual center through the optic nerve, thus producing vision. Therefore, the eyes have both refractive imaging and photosensitive energy exchange. Since the French invented the world's first optical camera in 1826, people have compared the human eye to a living camera, because the camera has a lens, an aperture, a black box, a negative and an adjusting device. The same is true of the structure of the human eye. Cornea and lens are equivalent to lens, pupil is equivalent to aperture, choroid is equivalent to black box, retina is equivalent to negative film. It has been nearly a hundred years since this formulation, but it is still highly praised by the medical community because such a comparison seems reasonable. But in recent years, I don't know what happened. Modern people's eyes are getting closer and closer. Some people think reading in dim light will hurt their eyes. Norman, a famous German ophthalmologist, explained to people that reading in dim light is harmful to eyes, which is a common misunderstanding. When the light is bad, although the eyes and brain are more nervous than normal people, it will not hurt the eyes. It's like taking pictures in the dark. Although the photo is not very bright, the camera will not be damaged. Although Dr. Norman's explanation is completely in line with the principle of ordinary cameras, I believe that it is unthinkable for any parent (including Dr. Norman) to let their children read and write in dim light if conditions permit. Why is this absurd logic completely inconsistent with reality? This is obviously directly related to the principle that we use outdated ordinary cameras in medicine. Ordinary cameras have shutters, so they have black boxes. Without the shutter of the eyes, the choroid cannot form a black box. The negatives of ordinary cameras are imaged one by one, while the images obtained by the eyes on the retina are continuous. When strong light shines on the eyes, it will stimulate the retina, causing glare reflection, glare reflection-but it disappears, which often indicates that the midbrain is damaged. However, if strong light shines on an ordinary camera, it will only overexpose the negative film without damaging the camera. When the light is weak, only the camera film is weak. However, reading in poor light will not only hurt your eyes and shed tears, but also make your brain feel tired, so that your vision is blurred and your handwriting is shaky to the point where you can't see clearly. The distance between glasses and books is naturally getting closer and closer. In the long run, in order to adapt to the situation of close reading in weak light, the eyeball is distorted in various ways, which makes the image entering the pupil unable to focus on the retina accurately, thus causing myopia. The difference between the two is obvious. So what principle is reasonable to compare the visual process of the eyes? Of course, it is still the principle of camera, but this is not an ordinary camera, it is a digital camera. According to the working principle of a digital camera, light focuses an image on the surface of an imaging photoelectric sensor chip (CCD) through a fixed lens, and the CCD decomposes the image into a total of about 6.5438+0 million pixels, and converts the light shining on each pixel into charge and then into voltage. Then the voltage matrix representing the image is sent to the microprocessor for processing to form an image. This process can be continuous-that is, a digital camera can shoot continuously (or be used as a video camera), which is consistent with the process of people seeing things. The human eye has cornea, lens and pupil similar to lens and aperture. The light passes through the cornea, lens and pupil and reaches the retina, which decomposes the image into 65.438+0.23 billion photosensitive cells and then converts them into voltage. The voltage matrix representing the image is sent to the brain for processing, and then we are very familiar with vision. If we regard each photoreceptor cell (cone cell and rod cell) on the retina of the eye as a P-N junction, there are about 65.438+0.23 billion P-N junctions distributed on the retina. When visible light irradiates these P-N junctions, photogenerated electrons are generated, and these photogenerated electrons gather together to form a photoelectron flow. These photoelectron streams carry a large number of point photoelectric information of external plane images, which are sent to the visual cortex of the brain through a total of about/kloc-0.0 million optic nerve fibers. The vision produced by this technology is essentially different from that produced by ordinary optical cameras. If we can confirm that the visual process of eyes is based on the principle of digital cameras, many special functions of eyes that are similar to digital cameras and unknown to people will be displayed. Because digital cameras can see through, as long as you have a digital camera, anyone who wears clothes in the street may be photographed naked. In 2002, with the appearance of digital cameras in Guangzhou, this horrible thing will happen at any time. The digital camera DSC-F707 produced by Sony can completely change people's understanding of the visual function of eyes: the camera has 5.02 million effective pixels, 10 times accurate digital zoom, 5 times optical zoom, F2.0 professional Zeiss lens, night shooting and night shooting functions, and has a perspective effect. It can see what is behind through sunglasses; If the handwriting is altered, it can also be seen through the smeared handwriting; You can also see the covering below through the tulle. In other words, you can see other people's bodies through their clothes. Many people go to Thailand to watch fashion shows with this camera, through which they can see the nude models. You can also take pictures as a souvenir. The model in the lens seems to be covered with a thin layer of spun yarn, and the body under the gauze is clearly visible. In principle, the so-called perspective photography, that is, infrared photography, is to use infrared rays to shoot things invisible to the naked eye, especially at night. Although its principle is the same as that of ordinary photography, the difference is that infrared photography uses invisible infrared light as lighting source. Because the wavelength of infrared light is longer than visible light, some materials and textile fabrics reflect less than visible light. This effect is that infrared light passes through the fabric, is reflected by the object under the fabric, and passes through the fabric again. This effectively makes the fabric look translucent, similar to very transparent clothes. Sometimes, in this case, the fabric is almost invisible, forming a nude effect. However, not all clothes can see through. Apart from pure cotton, which is the safest material and cannot be seen by infrared rays, nylon and cotton blended clothes can be seen through (especially in swimming pools and other places, wet clothes are more clear). The perspective of pure nylon and silk materials is above 75%. Using the perspective function of infrared rays, some objects covered by some objects can be photographed. For example, you can take images of objects under the sand through thin sand. Using ink to shoot altered documents has been widely used in public security criminal investigation. In fact, most digital cameras have infrared shooting function. Just add an infrared filter.

The above examples show that using ordinary optical cameras or digital cameras to explain human visual processes will produce two completely different results. If we think that the human eye also has the perspective function, then the human eye must have a physiological structure similar to that of a digital camera. Fortunately, modern ophthalmology has revealed the basic characteristics and structure of this structure. The difference is that there are about 65.438+0.23 billion P-N junctions distributed on the retina of human eyes, while the most advanced digital cameras have only a few million pixels at present, which causes a huge difference in resolution of at least dozens of times. This alone shows that the perspective function of human eyes should far exceed that of digital cameras. Even from the interpretation of modern ophthalmology theory, this conclusion is undeniable. This forces us to question the existing ophthalmology theory.