Don't you hate it when you see something beautiful, and you pull out your camera, and you just can't make it look the same. What is wrong here? Is it me or the camera?! When you think of a robotic version of a human eye, or even a prosthetic eyeball, you probably picture some kind of camera. It makes sense, they both capture images and video, but aside from general comparisons, they're really not the same at all! When you're looking out through your eyeball, it's doing the same things as a camera, adjusting the lens, focusing and trying to make the image look as good as possible. In fact, generally speaking, both the eye and a camera have a lot in common! Both have adjustable apertures to let in the right amount of light, both have a lens, and both have a way to absorb the light. But from there, comparisons get a little fuzzy.
The reason your photos don't look the same way your eye sees them is because of the way the two different mechanisms function. The eye is 28 grams of vitreous fluid, muscles, cells and nerves. Cameras can be formatted and customized to do thousands of different types of shoots. When focusing, the lens of the eye uses the ciliary muscle to change its shape, a lens needs to be physically moved. When it's bright or dim, the pupil uses the sphincter pupillae to adjust the amount of light being let into the eyeball -- a camera uses an aperture to adjust the amount of light. According to research conducted in Canada in the late 50s, the f-stop of the human eye might be around f/3.2 to f/3.5… It was cited a lot, but I couldn't find the study to double check. Regardless, cameras have a far wider range of f-stops and ISO sensitivity to pick up dim light. When a full-frame camera absorbs light, it does so with a 35 millimeter sensor, compared to the eyeball -- which has a retina at the back. That wall of cells is CURVED, but is almost the same exact size as the camera -- about 32 mm! The difference is, the retina isn't very clear. We can only see 20/20 at the macula, or fovea. A spot on the retina that is ALL cone cells. Outside of the fovea are a mix of rods and cones, followed by just cones at the edge. This is why you can't read something you're not looking directly at, and why peripheral vision is mainly just for movement. Additionally, your eye only sees color where there are lots of cones, so closer to the fovea the more color.
A camera, by contrast, can pick up detail across the whole of the sensor, all in color! However, even though the camera can see a wider field, the amount of information is relatively low. Most high-end cameras process around 24 megapixels, but the human eye can get 52 megapixels on average and HUNDREDS of megapixels if you take into account the whole field of vision! It get's pretty ridiculous. What you see isn't just one image, it's dozens or more! You don't worry about overexposing, shutter speed, or aperture because your brain does that for you and filters out any errors in color or depth. In the end, the reason your photos don't look like what you see, is because what you see isn't really real. It's what your brain created while sucking in all that visual information and compiling it into a three dimensional, multi-million-pixel world.