If you shoot a fluorescent lamp in iphone's 240fps slow-motion photography mode, it will flash, but if you shoot an LED lamp, it will not flash. Isn't it studying under the fluorescent lamp?

You just know, why not buy eye protection lamps? Fluorescent lamp is a 50HZ commercial power supply. When they flash 50 times per second, the eye protection lamp of the lamp tube only increases the flash to 100HZ through circuit frequency conversion. In fact, the simplest test method is to make a small circle with cardboard scissors, draw a thick line through the center of the circle, tie a toothpick at the center of the circle to make a gyro, and turn it under the lamp. Even if it's gray, it doesn't flash, but it flashes like chrysanthemum petals, which will definitely hurt your eyes.