There's a lot of information out there about designing the web for accessibility. Over the last 10 years, the world has learned a lot about how to accommodate a vast diversity of different needs and abilities.
So, when it comes to designing virtual experiences, we don't need to start from scratch. Here's a few things you should consider from a VR Accessibility point of view.
Seated-first design
Like responsive web design, which accounts for the screen size of the user, VR experiences should be responsive to height and posture. Consider audiences who use wheelchairs, are unable to stand for long, or are short (including children).
- Don't place buttons or interactive elements in hard to reach positions
- Ensure that NPC eye-gaze includes height, not just direction
- Include locomotion options which can be done from a seated position
Audio cues
VR experiences shouldn't rely solely on audio cues to grab a user's attention, or require audio in order to complete a task. Not only does this allow your experience to be accessible by hearing impaired people, it also let's users play on mute if they want to.
- Provide a subtitles option for speech
- Provide visual indicators where positional audio is used
- Provide visual cues for success or failure events (e.g. failure to start an engine should be visible as well as audible)
Readability
Current hardware resolutions make it difficult enough to discern text as it is. But as the resolution of VR headsets increases, don't be tempted to reduce font sizes to match resolution. Consider users with a vision impairment that may not be able to make out small text.
- Recommended font size is 3.45°, or a height of 6.04cm from the distance of one meter
- The text should be faced perpendicularly to the observer, and rotate around the observer's view
- Use a line length of 20—40 symbols per line. With bigger fonts, lines should be shorter.
More information on fonts in VR can be found in Volodymyr Kurbatov's article.
Colour
Color blindness or color vision deficiency (CVD) affects around 1 in 12 men and 1 in 200 women worldwide. This means that for every 100 users that visit your website or app, up to 8 people could actually experience the content much differently that you’d expect.
http://blog.usabilla.com/how-to-design-for-color-blindness/
Virtual worlds tend to be visually rich, which often means a much broader range of colour than one would typically see on a website, or even in the real world. With this in mind, strive to ensure that colour isn't used a the only way of displaying contrast.
- Choose a variety of textures to provide better contrast between visual elements
- Use both colours and symbols in interface design
- Avoid "bad" colour combos (e.g. Green + Red, or Blue + Purple) for primary elements
VR is still in it's infancy – we're still learning about what works and what doesn't. As the industry grows, it's important to continue prioritising accessibility, so that our virtual stories, games, environments, and tools can be explored by everyone.