The HMDVRDevice interface of the WebVR API represents a head mounted display, providing access to information about each eye, and allowing us to modify the current field of view.
The getEyeParameters() method of the HMDVRDevice interface returns current parameters for the eye specified as its argument ("left" or "right") — stored in a VREyeParameters object.
The setFieldOfView() method of the HMDVRDevice interface can be used to set the field of view for one eye, or both eyes simultaneously.