I see multiple black lines inside that. Your backlight uses PWM dimming if you have more than one gap per vertical line.
(Can also be some smartphone sensors that takes multiple photos per longer-exposure photo, but that is another Pandora Box)
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Now that being said if you fix your PWM dimming problem (and have only ONE black gap per visible line), then the next weak-link domino is that your eye-tracking accuracy can influence this.
Some people have shaky eyes during eye tracking, and some have very smooth-tracking eyes. Shaky eyes (saccades) can cause black gaps to momentarily reappear. Younger people with good eyes that moves at a more constant speed (rather than stop-go-stop-go motion in eyeballs) during eye tracking -- will see a perfectly solid white background with zero black lines.
If you don't pursuit perfectly, you will have artifacts like briefly-reappearing black lines. if you pursuit very well, the black lines won't reappear. This varies significantly from person to person.
Just because you see a faint amount of black lines (e.g. whether 1% or 5% or 10% black lines) you're still 90% accurately eye tracking. If you had ZERO thickness increase in the vertical lines, then there's a weird behavior in your display motion blur perception. But if you see the lines thicken by more than 50% and the black thin by more than 50% to the point where most of it is "solidified" (like the photo), then you're closer to normal than not. However, I track eyes better than that and can manage to make the black lines completely disappear with the accuracy of my own eye tracking, at least at the ~80fps scale. It is wholly possible that your eyes can't rotate as smoothly as mine can, but even if you can only do 80-90% accuracy, you're still subject to the competitive advantages of this FAQ. Even 90% motion blur will still osbscure a tiny enemy or a tiny nametag above a person.
Please note that I'm using
metaphors about lines and stars. In one specific game lines might be a camoflaged distant enemy (10 pixel tall) running through a dense forest, and stars might be the stationary collectables inside a forest. Or in another game, the lines might be the ball in Rocket League, and the stars might be the other players in your peripheral vision. Or it might be vice versa. Again, they are
metaphors. X means X and Y means Y, where the lines may metaphorically represent one thing in a game and stars may metaphorically represent a different thing in a game.
For the vast majority, it's easier to see the "stars" (tiny gaps in vertical lines) when staring at the second UFO, regardless of whether you're strobing or not.
Now, for a more real-use case (that is less metaphorical)
Let's move to
www.testufo.com/map at 120Hz+
Try to read a street label without strobing. It's harder.
Try to read a street label with strobing. It's easier.
Even though the strobing is laggier, you were able to read the street label better. This could be the nametag or enemy in a blurry pan of DOTA where you're rush-panning/turning/scrolling while trying to pay attention to things
before the screen stops panning/turning/scrolling.
The bottom line is:
- Sometimes you need the lowest lag
- Sometimes you need the strobing advantage
The metaphor at the start of this thread is simply to illustrate the tradeoffs of strobing, and to
help the user decide whether strobing might be worth trying for them. Understanding which game to use strobing in, and which game not to use strobing in, varies a lot from person to person, and sometimes the human reaction time will go down with strobing (reduce human lag more than the increase in system lag). The fetishization of latency numbers need to be nuanced by the complex latency chain where you have concurrent increases and decreases elsewhere, creating a different total. And the lag chain includes the human: