VR Screenposition or HMD location in material

I have some particles pretty close to the player camera and I’d like to lower the opacity of the particles in the center of the screen. I can get it to work fine normally using ScreenPosition or CameraVectorWS in my particle material but when applying it to vr the effect breaks because of the offset of rendering both eyes.

Is there any way to get the HMD location/vector or an average position of both eyes within the material?