How are you grabbing PD and OC heights on wiggly 3–5 year olds without spooking them? The i.Terminal camera feels like a spaceship to some kids; I get steadier readings with a simple digital pupilometer and a tiny ladybug LED at about 40 cm while I narrate and let them try the “magic light” first. Any kid-friendly targets or brands you trust for calmer centration?
I ditched the i.Terminal for 3–5s — “spaceship” vibes indeed, . I use the digital pupilometer but swap your ladybug for a soft yellow LEA fixation sticker on my phone at about 40 cm, do monocular PDs, then quickly dot OC on the demos with a wax pencil while they watch; heights come right off the dots. The Good-Lite LEA stickers are cheap and non-spooky: https://www.good-lite.com/ — do your kids track yellow better than red?
I get steadier readings by putting a small blue cling dot on a mirror at their eye height — ask them to “find the dot” and you can snag monocular PDs and mark OC with a wax pencil before they blink. If mirrors ramp them up, I switch to the parent’s nose as the target at about 40 cm and keep the pupilometer low and out of the child’s sightline. Have you tried that mirror trick, @lucinda_g?