Generally, people who are new to the laser cutting machine like to stare at the cutting head. If they look at the sparks generated by cutting for a long time, it will hurt their eyes and cause a tingling sensation. During the processing of laser cutting machine, the characteristics of the laser emitted can make the energy highly concentrated in space and time. The image is formed by focusing the refractive medium of the eye on the retina, and the energy density on the retina is 104~105 higher than the incident energy density on the cornea; Laser monochromaticity is good, and the color difference in the fundus is small. The extremely low laser energy can cause damage to cornea or retina.