>>338920627
I don't think you know what I'm talking about maybe? oculus, vive, index etc all have their own settings for their lenses from the factory something you never need to even think about unless you mod your headset (only vive/vivepro have lens mods that I know of so oculus is irrelevant) The mod I'm speaking of is taking the glass lenses from a 2017 gear vr (black one not the white one and swapping them into 3d printed mounts that properly line them up to fit into a OG vive or vive pro. These lenses aren't frensel lenses so they don't suffer from godrays and they have increased sharpness and sweetspot compared to the original lenses. There's a software fix that you apply in steamvr config files that fix the distortion from the different lens profile. Not that I found the distortion much worse in game without the fix but it worth applying nonetheless. 
>>338921034
Only serves any purpose if it's the black (2017 model) and you have a OG Vive/Vive Pro. (maybe someone will make it worth with vive pro 2 in the future but probably not since the lenses aren't the same anymore) I spent like 270 for my entire vive setup and I spent another 25 bucks on ebay for the gear vr 2017 and printed the mounts myself. I wouldn't buy a gear vr off of craigslist as they are still around 30 bucks on ebay in "like new or open box" condition. 
>>338919398
What I'm talking about isn't using the gearvr with a phone. That is a garbage vr experience but applied into a proper vr headset the lens optics are actually pretty good.