Reminder that the main reason people notice a big difference in FOV when going to Index from Vive is because they never experienced the full FOV the Vive offered. Those who got their eyes closer to the lenses by using a thinner facial foam perceived a very slight improvement in FOV when moving to Index. The Rift and Rift S therefore are also better than most people think once installing a thinner facial interface. The Index used larger lenses and a better distance adjustment so that people could get the lenses closer, and that resulted an increase in mean effective FOV.