After focussing on the dot for a few seconds the images appear to produce a tunnel or other change in effect from just images flipping, maybe a moving star. Then when the grey image appears you get an after effect of the overall image for about a second. Some feel a form of pressure or even light seizure sensation in the brain and have auditory experience like there was a sound that disappears each time the grey clearing screen appears.Then afterwards some people feel a bit cognitively fatigued, drunk even for a few minutes to hours.
It feels odd, its hard to describe it feels like something weird is happening in the brain.
Interesting. So I do get the over-shadow effect for about 1.5 seconds but I get that from any bright light that transitions to a grey background mostly from taking high dose benfotiamine, along with lutein and astaxanthin and chelated copper as my nervous system was being depleted of thiamine due to a dumb self induced issue that I have nearly resolved. Maybe I am not a good test subject for that reason. Or perhaps my monitor is too bright.
Edit: I reduced the brightness, contrast and changed the black mode of the monitor and went through several cycles. I still get the over-shadow effect for anywhere from 1.5 to 2 seconds but no other effects. Perhaps my supplements are interfering or confounding. I guess it may be useful to note what supplements the test subject is consuming along with dosage to determine if that is a confounding factor.
It feels odd, its hard to describe it feels like something weird is happening in the brain.