Troubleshooting the installation
If you experience double vision, or feel like the image (field of view) is too
small try scanning the appropriate QR code for your phone with the Google
Cardboard app.
Go to the Google Play store, search for Google Cardboard and
install the app. (Link to app)
Once you start the app, you'll be prompted to accept the terms
of service and configure your phone for VR.
To do so, you'll have to give the Cardboard app access to your
camera.
Scan these codes, smallest to largest, until you find the right interpupillary
distance for your eyes.
You will be greeted with a screen confirming you've successfully set up your
phone. To apply the changes, restart your phone.
And if your phone is bigger than 6.1", use this QR code for the setup:
Interpupillary distance less than 62mm.
Interpupillary distance between 62mm and
64mm.
Interpupillary distance greater than 64mm.