Why does the computer CRT monitor screen flicker when viewed with a SLR lens, but does not flicker when viewed with the naked eye? Why?

Standard CRT flashes 85 times per pixel per second so that the human eye cannot detect the flicker.

(If the screen refresh rate is adjusted to 60HZ, it will be very dazzling, and if it is lower, you will see flickering.)

And the pixels of the CRT are moved line by line by the internal electron gun. Or interlaced scanning means that the pixels are lit in sequence, rather than all pixels lighting up at the same time according to the light-emitting principle of the liquid crystal (LCD displays usually light up 60 times per second)

The reflection speed of a digital camera is not as fast as It refreshes so many times per second. Generally, 24 or 30 frames per second are used when recording, so the trajectory of the screen being lit up diagonally is recorded.

I don’t know if I made it clear.