Eye Relief
What is it?
Eye relief is usually referred as to the distance lying between the eye and the lens/display of the HMD. It is generally measured in millimetres, and it can vary between subjects owing to the different facial physiognomies or how tightly the headset is fitted to the person’s head.
How is it measured?
There have been presented different approaches to measure it. In our study, we propose the use of a custom 3D printed hollow cylinders (check our Download page) along with small paper tubes.
The small cylinders are glued using double side tape to the lens surface, and the small paper tubes are placed inside the hollow cylinders. The subjects wear the headset with the eyes closed, and the eyelid will then push the piece of paper deep inside the cylinder.
After removing the headset, a calliper is used to measure how deep the piece of paper went into the cylinder (a.k.a. the eye relief distance).
Further details are given in our paper.
Eye relief table
| HMD | Mean eye relief (mm) | SD(mm) | Range(min-max) (mm) |
|---|---|---|---|
| StarVR One | 18.2 | 1.7 | 15.8-23.9 |
| HTC Vive Pro | 17 | 2.2 | 14.5-24.6 |
| HTC Vive | 16.6 | 1.9 | 14.4-23 |
| Pico Neo 2 | 18.3 | 2.1 | 14.8-23.2 |
| Oculus Rift DK2 | 10.7 | 0.9 | 8.6-13.6 |
| Fove 0 | 11.4 | 1.7 | 8.4-15.9 |