Most of us, open our eyes, can see this colorful world. People often say that the eyes are the windows of the soul. Vision is the higher feeling of human beings. It is not only a simple view, but also includes many complicated functions such as distance, three-dimensional, shade, color, etc. Huh? Are we what how saw? Our vision system is very similar to the imaging principle of cameras. External objects refract light, which passes through the eyeball and shines on the retina. The retina is equivalent to the [negative] in the camera, where an image is formed. The optic nerve on the retina transmits the electrical signals of the [negative] image to the visual cortex of the brain, and Read More …