This is why so many drivers pull out into the path of cyclists and motorcyclists. They look both ways and totally fail to see them.
The camera will adapt the recording to the light level of the room, so it’ll be difficult to evaluate if the digits brightened or not. He needs to leave the phone in the room recording the digits. If the effect is not noticeable every time he might need something capable of just taking a picture every two seconds (or similar).
When I did my undergraduate in psychology I took a course on perception.
I’m not sure if this is the same phenomenon or simply related, but one of the interesting things I learned was the way human (and other species) vision works is when we stare blankly either near or far (not moving your eyes whatsoever), after 10 or 15 seconds our field of vision basically blends together.
If there is then any motion at all in our field of vision our eyes are immediately drawn to it.
The context of this was that animals perceptions are designed primarily perceive changes in state. If the same stimulus is given constantly we stop noticing it. The olfactory example being how you don’t smell your own cologne or perfume but others can overwhelmed when they come near you.
The professor said a common example of this is how a bird hunts. Their heads and eyes remain perfectly motionless so when any insect moves in their field of vision they immediately spot it. Similarly, prey animals will keep their eyes and heads perfectly still if they think they are being stalked. That allows them to immediately detect where the predator is coming from.
I actually do this frequently on hikes in the woods If I think I see an animal in my peripheral vision. It works shockingly well