Personally, I feel like my field of view is much smaller. Like 180 degrees overall. I can't see my cheek or eyebrows

I believe that for some of the VR headsets, in order to improve graphics to the point where it is indistinguishable from human vision (e.g. 120+ FPS and 4K+ definition), certain optimizations and tricks must be employed as our hardware technology is not yet advanced enough. For example, I heard that since the way human vision works is that we only see the object we are focusing on in the center of our eyes the most clearly while the peripheral objects are blurrier. As a result, one trick that VR headsets use to achieve high quality graphics with limited hardware is to use eye-tracking technology to only render the areas the eyes are focusing at high definition and frame rate. The result is indistinguishable to one that renders everything at high quality. In other words, the main concept is to not waste computations on things that our eyes won't "see" anyways.

Additionally, I think it may feel like the human visual field of view is smaller due to overlap between fields of view over both your eyes. For instance, I read that each individual eye can see your nose, but the brain splices visual data from both your eyes to remove your nose and other blocking elements from your field of view, so the primary field of view you have from your eyes doesn't directly translate to the image you see in your head when you look around. I'm not 100% sure, but that probably explains some degree of why we feel our field of view is smaller than what it actually is.

And another reason might be we only focus on a small area of what we see, which give us the feeling that our fov is small. But when you are using a VR headset, you can tell the fov of it is smaller than what you see in the real world.

That's a really cool thing to think about. This isn't directly related, but on the note of eye-tracking: for the Apple Vision Pro, it uses eye tracking to distinguish which button the user wants to click/actions the user wants. However one thing that users have reported being difficult is that the way human sight works is that we often move on from looking at the item we wish to select/pick up/use before we actually physically signal-- so users have reported that they have to retrain their eyes to stay on buttons for longer. Just thought it was interesting, although perhaps not directly related to FOV.

This recalls me a intersting fact: Our brain typically filters out the image of our nose from our conscious visual perception. Although our noses are within our visual field and can be seen if we focus on them, our brain chooses to ignore them through a process known as "sensory adaptation" or "perceptual adaptation."

It's interesting to ponder how the expansive range of human vision has influenced cultural and architectural design throughout history. For example, wide panoramic views are often celebrated in landscapes and city planning. Think of the design of an amphitheater or the layout of a panoramic viewpoint in a national park. These are deliberately created to maximize our visual field, catering to our nearly 200-degree binocular view. In art, the use of techniques such as foreshortening and perspective takes advantage of our visual field to create a sense of depth and immersion. Artists play with these concepts to draw the viewer's eye across a canvas, knowing that the peripheral vision will fill in context and add to the overall experience of the artwork. Moreover, the understanding of our visual field has implications in the development of assistive technologies. Consider the design of eyeglasses and contact lenses; they must account for the wide range of human vision to be effective. Advances in these technologies could provide personalized fields of vision correction based on individual visual field assessments, potentially offering enhanced visual experiences tailored to our unique physiological characteristics.

I think it's really interesting to think about the field of view in our eyes, because as some other people have said, when some parts of your body such as your eyelids, nose, and cheeks block parts of your view, your brain usually just ignores it. I think it's so interesting how we can just piece our field of vision together too, from both eyes, and still make sense of it. To us, it's so seamless, it doesn't even really feel like we have two eyes most of the time.

I never thought of my field of view this way! I know your brain automatically filters your nose out of your vision unconsciously, but it's cool to see how it actually affects the field of view if you only had one eye. I find it very interesting how this is a factor that needs to be taken into account when making VR headsets. Pixels in the blindspot areas wouldn't be seen unless the user actually moves their eyes up, which could present some problems in some visual mediums. Certain games or videos could accidentally put important information in the blind areas, making the user unable to see them. Also, its interesting to think about how someone with one eye or partial blindness in one eye would experience VR differently. I wonder if specialized headsets could be made for people with conditions that affect their field of view.

On top of accommodating for human's visual field of view, I think it can be interesting to leverage the simulation capabilities of VR to present what visual fields of view look like when viewed from other species' perspectives (eg species that have eyes on the side, more than 2 eyes, etc.).