Can short-sighted people use virtual reality without glasses? I asked an expert

This is something I was wondering after chatting to my friend Richard at the games festival EGX Rezzed. I’ve tried the Oculus Rift and the HTC Vive (writeup here), and was blown away by both – but I had my contact lenses in. Would I have been able to see without them?

To my mind, it would make total sense if you didn’t need corrective lenses for VR, because the screens are right in front of your eyes. That means there’s no actual distance, only pretend distance shown on the screen. But it turns out I’m wrong. I asked Gordon McKenzie, Co-Founder and Director of Clinical Development at Michelson Diagnostics (a British medical imaging company), who worked on some of the early-stage virtual reality tech at Sira, and also has a PhD in Medical Lasers (lasers!). And he told me:

The reason VR doesn’t work for short-sighted people [without vision correction] is that optical distance and actual distance are two different things.
If you’re looking at something that is far away, then the light is basically coming in at a much shallower angle than if it was nearby. The rays are almost parallel, so the eye needs to do less work to focus it onto the retina. Most people would not be able to focus on a screen right in front of their eye, so VR systems use an optical system (basically some lenses) to do the focusing to make it act like it’s a lot further away.
So, if you vary the strength of the lens, you can do more or less of the work that the eye would otherwise have to do, but you won’t correct for astigmatism or any other fancier factors. Hence normally optical systems are set up at infinity, and the user can just wear their glasses.
The thing that makes you feel sick is partly because you think you’re moving, but partly because the brain is confused by being able to look at near and far objects without having to change focus. Some of the newer systems will presumably deal with this and should massively improve the experience for all.
There’s also a bit of info on the Oculus forums (thanks Sam) – some useful quotes:
Near or farsightedness can be addressed at least partially in the Rift by using the alternative lenses provided with the dev kit. Some of them are beyond the power of the Rift to impact. Loss of vision in one eye is likely to be something the Rift can’t help with. There’s nothing the Rift is able to do in rendering to a single eye that you wouldn’t be able to do on an ordinary monitor, so it’s not going to provide any special functionality other than a wide field of view.
So the Oculus Rift comes with a set of lenses that help correct for milder eye conditions. That’s interesting. But if that doesn’t work and your glasses don’t fit, you might be out of luck:

Some glasses simply don’t easily fit inside the Rift’s frame, but most do. If your eyesight isn’t too poor, then you will probably be able to use the Rift without your glasses. Even though I’m moderately nearsighted and have astigmatism in both eyes, I prefer not to wear my glasses.

I personally haven’t heard anything about the possibility of ordering prescription lenses for the Rift. Due to the cost of manufacturing custom lenses, I doubt it’s a service that Oculus will provide, but maybe a third party will set it up.

Hear that, opticians? Us geeks have terrible eyesight due to staring at screens all the time. If you can be the first to manufacture prescription lenses for the Oculus Rift or HTC Vive, you’re going to be rich.

One thought on “Can short-sighted people use virtual reality without glasses? I asked an expert

  1. Joris says:

    Thanks for the info. Seeing as I’ve only got -1,5, I’m hoping I’ll be fine. I might buy some cheap, off-the-shelf lenses if it turns out they’re a noticeable improvement.

    Damn, I’m really feeling like I’m buckling up already. Let the VR wars begin!

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