When designing UI elements and interfaces within a virtual environment, real-world physical ergonomics should be taken into consideration. Be sure to keep head rotations within comfortable ranges — especially when using gaze targeting, or for longer durations or more repetitive tasks.
Assuming a person is sitting or standing still and focusing on an interface, the most important UI elements should stay within a 94° horizontal and 32° vertical space.
The main elements that you’re wanting to be within the user’s field of view with a comfortable head turn, should be within a 154° horizontal space. An easy way to measure this is to hold your arms out straight and place your hands where they are still visible within your periphery.
The maximum required head turn should be kept at or below 204° horizontal — or where your arms are stretched out as far behind you as they can be to the sides.
TL;DR Do’s and Don’ts
- Keep physical ergonomics in mind.
- Try to keep the head in a neutral position as much as possible.
- Ensure head rotations are within comfortable ranges.
- Don’t design environments that require extended or repetitive look-up or look-down interactions.
A result of extended look-down interactions
This has only recently become a widespread issue since the invention of the smartphone. The longer someone holds up a phone to interact with it, you’ll notice the arm begins to lower and the neck begins to bend down. This can cause a lot of pain and stress on the neck from being bent for long periods of time. The lower the neck bends, the more pressure is put on the neck. This medical condition is called “smartphone neck” or “text neck”.
When you look down at a phone, your neck has to work harder to hold up your head. Tilting your head 60 degrees puts 60 pounds of force on the cervical spine.
— Dr. Ken Hansraj, Internationally Recognized Spinal & Orthopedic Surgeon
If you add on the weight of a heads-up display, this could increase the amount of pressure on the neck even more.
- The Measure of Man and Woman: Human Factors in Design, Revised Edition by Alvin R Tilley, Henry Dreyfuss Associates
- Assessment of stresses in the cervical spine caused by posture and position of the head by Kenneth K Hansraj
- Content Zones for VR by Mike Alger
- Storyboarding in Virtual Reality by Vincent McCurley
- VR Paper Prototyping by Saara Kamppari-Miller
If you enjoy these articles, consider supporting me on Patreon.
I’m an Immersive Tech UX Design Professional with over 22 years of experience designing for kiosks, websites, mobile apps and desktop software for many well-known and not-so-well-known companies.
I’m not speaking on behalf of or representing any company. These are my personal thoughts, experiences and opinions.