HTC Vive Focus 3 can now be upgraded with eye and face tracking - Pocket-lint

... Focus 3 to upgrade and offer a more natural and convincing VR experience. ... to offer users a more immersive experience in virtual reality.

source https://www.pocket-lint.com/ar-vr/news/htc/162605-htc-vive-focus-3-can-now-be-upgraded-with-eye-and-face-tracking