Your eyes have a flicker rate too. It works much like a digital video camera in that it takes an electronic image from your retina and passes it through the optical nerve to the brain. In very young children, the optical refresh rate, aka flicker rate can be as high at 60 fps or higher. No one knows for sure.
BTW, the flicker rate for most ballasts is only 60 Hz because most of them only conduct on one half cycle. They rarely use a full wave rectifier due to costs. CFL’s for some reason, not sure why but the bulbs fluorescence is more persistent, similar to an incandescent bulb so it doesn’t turn completely off. Some LEDs filter the pulses into a DC so they stay on, some flicker at 60 Hz like most long tube fluorescents.
Anyway, back to the subject, your brain can freeze frame something for about a half second or less so a ceiling fan at low speed and momentarily freeze the blade in position. This happens more as you grow older as your flicker rate slows down with age.
The slowing of the flicker rate is why older drivers slow down. Things move more between each refresh of their eyes so things appear to be moving faster to them. Your reaction time slows down as your age partly because of the lower flicker rate.
Young to middle age adults typically have a flicker rate of around 30 fps, children and teens can have a flicker rate of around 40 fps. Film movie cameras took movies at 24 fps, as fast as they could go when the technology was first developed, (8mm filmed at 16 fps). The movies would appear to flicker badly when played back on a projector that projected at the same rate. Movie projectors were changed to project each image twice to give a 48 image per second rate which is higher than most people internal flicker rate so the movie appears to flow smoothly. TV vidicon cameras, analog recording on magnetic tape, filmed at 30 fps, analog TVs would again project each image twice but offset a half line so there is no visible flicker and no lines on the screen. Old movies were televised using a special projector that would alternate showing each frame of the film, with 3/2. That is the first frame would project 3 times, the next 2 times getting the 24 fps movie to keep time on a 30 fps TV.
Now to go off track a bit. I developed a theory when working with schizophrenic patients that they seemed to be very sensitive tot he flicker of fluorescent lights. They would calm down (somewhat) almost immediately when going outdoors or when the fluorescent lights were turned off and would become more agitated when exposed to fluorescents almost immediately. My theory is that they may have much higher flicker rates than most of us.
Long exposure to flicker can also cause something called flicker vertigo. This commonly affects helicopter pilots. Long term flicker vertigo can lead to brain damage.
From this, I came up with another theory. Babies are believed to have much higher flicker rates (theory only) which could make them sensitive to fluorescent lights used in hospitals. I wonder if the rapid increase in children with ADHD could not be caused by that early exposure to fluorescent lighting.
Also schools now have windowless classrooms with fluorescent lighting and I wonder if that is contributing to kids having more learning disabilities.
Just something to think about.