cancel
Showing results for 
Search instead for 
Did you mean: 

VR for the visually impaired - the first experience

progmars
Honored Guest
Hi everyone.
TL;DR:
 
Your distance prescription might actually be not the best for VR! It's worth considering other options, if possible, and if you can find a doctor who can help.
 
The long story.
 
I'd like to share my experience in case it's useful for other visually handicapped people. Of course, our vision issues can be very different. Still, this might help you to consider possible caveats before buying a VR headset.
 
I have been visually handicapped since birth. In simple terms, my optic nerve "does not have enough resolution" and I need to bring everything closer to my eyes to see better. In addition, I have near-sightedness. For near vision, I don't need glasses, my best viewing range is 20 - 30cm. When I was young, I could focus even closer, at 10cm. 
My distance vision is tricky though. After 50cm, my vision can be improved with myopia glasses. However, it is known that negative diopters make things both sharper and smaller. For a person with healthy optic nerves, seeing things smaller is not an issue, they just need to remove blurriness.
 
But in my case, smaller means less readable because of my optic nerve issues. So, I use my distance prescription only outside of the home when I want to see things sharper (which relieves the eyestrain greatly) but not necessarily to be able to read stuff. 
 
Doctors usually tended to give too strong prescriptions, which seemed OK at the doctor's office but were too difficult to get used to and wear outside. So, after reading a few books on optometry and figuring out my problem and why it was so difficult to come up with a good prescription in my case, I bought an optometry trial lens set with a frame to experiment at home. When I achieved the most comfortable and safe lens combination, I verified it with a doctor to get my prescription. 
 
Being a programmer and a huge fan of VR sci-fi movies, I have always wanted to try out VR, but I was afraid it would not work well for my eyes. So I started it cheap. I bought a Google cardboard-based VR headset together with RiftCat software. The headset had an important feature - you could move its lenses back and forth, thus changing its focus a bit.
 
So, when I tried it I was impressed. I could adjust the lens distance from the screen (my Android phone) in order to see things clearly. I later found out that Cardboard lenses usually have a focus length of about 50cm, which explains why I did not need glasses. Of course, there were other issues to deal with - small HUD texts in games, etc., but I was mostly interested in archviz stuff and custom simulations and environments. Still, I wish there was a zoom option for HUD and menus in every VR game.
 
And now, based on my positive Cardboard experience, I bought Quest 3. When I turned it on, I got worried a lot. It was so unpleasantly blurry! I'm used to seeing things blurry in the distance all of my life, but this was different because of how VR works. The setup screen was there, as if right in front of my eyes. But my vision said it's much farther. I could not read the texts at all. I put on my distance glasses, and it became a bit better. Most of it was still unreadable because the text was too small (remember my optic nerve problem). Anyway, it was a next-next-finish process, so I got through it. A caveat - Quest failed to scan the QR code for the WiFi setup because my phone screen was too bright. But I figured it out and everything worked when I turned the brightness down a bit.
 
Still, the setup experience would have been much easier if the texts were larger.
 
When Quest was set up, I finally could lean closer to the main menu, yay! Also, I set the text larger in the Accessibility settings. However, I wish there was an option to scale everything larger, including also the icons.
 
I found out unofficial information that Quest has a focal distance of about 1.3m. That explains why my experience differs so much from Cardboard. 1.3m is too far away out of my best vision zone, even when everything looks like it's right in front of my eyes, especially when I move closer to the main menu. I miss the lens distance adjustment so much...
 
Then I started to think about my prescription lens options for Quest to make things better. I don't want to return it.
 
My distance prescription seemed too weak for Quest. So I took my old trial lens set and played around with it a bit. The results are strange. For example, -2 diopters are the best for me when looking at objects at a 1.5m distance in real life. My everyday distance specs are actually weaker (-1.5 diopters with +0.5 astigmatism correction). If I take a -3 lens, it's too much, it's blurry. 
 
However, in Quest, -3 diopters seem a good option. Even -4 diopters do not make things as bad as in real life! The difference between the lenses is not as noticeable as in real life. Also, switching trial lenses when using Quest is not easy. I have to be careful not to scratch the Quest lenses and still switch the trial lenses fast enough so that I can compare them. But I think I'll make things simple and stick to -2. I'll buy some cheap glasses with this value to use in VR for some time before buying the lens inserts.
 
Thank you for reading this long story. I hope someone will find it useful or entertaining.
2 REPLIES 2

kojack
MVP
MVP

The original Rift DK1 had a focal distance of infinity. 🙂

All of the Oculus/Meta headsets after that (and many VR headsets in general) tend to be around 1.5m, since that's a comfortable distance for many interactions.

Some headsets do have integrated diopter adjustment, such as the Vive Flow (per eye diopter), but I don't know if any of them are any good.

Author: Oculus Monitor,  Auto Oculus Touch,  Forum Dark Mode, Phantom Touch Remover,  X-Plane Fixer
Hardware: Threadripper 1950x, MSI Gaming Trio 2080TI, Asrock X399 Taich
Headsets: Wrap 1200VR, DK1, DK2, CV1, Rift-S, GearVR, Go, Quest, Quest 2, Reverb G2, Quest 3

Occupunk
Heroic Explorer

I guess my vision was pretty normal, but I'm older now and need about +2 to do any reading. For example, without glasses, I can not read my phone. However I do not use glasses for distance nor when using the quest 3. I've found that when I view my phone in pass through mode, I can read it fine without glasses. So although is "looks" like it is close to my eyes, it must be optically further away.