Sit a comfortable distance from the screen - you should be able to see the whole screen without moving your head.
Turn on the camera app on your phone, make sure its on video
Use the main camera, not the selfie camera
Turn on the flash light on your phone
Position the phone camera close to the eye to be recorded - around 2-3in or 5-8cm. Use a tripod or prop the phone up against a pile of books or similar
The phone should be below your eyeline slightly and angled up
If possible let someone check that your whole eye/eyes is clearly visible
Keep your head as steady as possible during the animation - preferably by resting your chin on a surface or holding your head in your hands
Start the recording on your phone before starting the animation
Follow the dot or pattern with your eyes as closely as possible, blinking as little as possible
Once the animation finished, stop the recording device
Watch the video to check that your eye is as clear as possible throughout
Visual Guide
The approximate distance and positioning required
Appropriate positioning/sizing for one-eye recording