One thing that worries me about wearing VR headsets for extended periods of time (whether for game or for work) is that your eyes are focusing at a single distance for so long. Not sure if there is any research to suggest extended usage is a problem, but it 'feels' like it could be. At least with a desktop or laptop, when you look around the room, you are actually changing your focal length.
From experience, I can tell you that you aren't focused on a single point, and in fact your eyes will change focus to look at objects in the distance just like in real life. In my virtual office set up, when I want to relax my eyes, I can look over my right shoulder and look at the office wall, or out the window, and my focus shifts. You can also make your screens as big as you want and as far away as you want, there are a lot of options to keep your eyes from looking at a single focal length for extended periods of time. My YouTube screen is also pushed back a bit from my normal monitor so I can shift focus for a few minutes every hour or so.
Your eyes do move, and they point at other stuff, but the focal length afforded by the lenses is fixed (it makes as if everything was at a few meters IIRC).
I also wonder what could happen if the ciliary muscle isn't used enough. Does it get weak and you rapidly get short-sightedness, or is occasional exercise enough?
Edit: maybe an answer could come from looking at people who recovered from extended comas. Does their visual acuity degrade? If not, that's promising. If yes, it could also come from other causes like the light of light (lack of UV light, especially during teenage years, has also been linked to short-sightedness).
> but the focal length afforded by the lenses is fixed
That seems weird to me because when I look at a screen at a different distance to the one I'm using I can see the other screens getting blurry just like in real life.
My guess is that this has to do with stereoscopic vision, not focal distance. Does the other screen become simply washed-out blurry or is it double-vision-type of blurry?
ok that makes sense. I actually just did this one eyed, and you are absolutely correct everything is in focus. So it must be just stereoscopy that looks that made me feel I'm focusing differently.
That said, it isn't any more or less strenuous on my eyes than IRL except when the text is too small. Font smoothing still isn't great, but if the screen is big enough you dont notice it.
This statement does not make much sense to me. In VR everything is at the same focal distance, you just fake perspective/parallax/size/stereovision to make it feel 3D. You can not change the focal distance if you just have a screen and fixed lenses. Even actuated lenses would not be enough as they will change the focal distance for the entire scene.
"Perceived distance/depth" has little to do with "focal distance" in this situation.
