Red laser is produced by semiconductor gallium arsenide laser. Because of its good directivity, when there is dust or fog in the air, you will see the laser propagate along a very thin straight line. Because laser is similar to parallel light, the working principle of the eye is convex lens imaging. When the laser enters the human eye, it will be focused into a small spot on the retina of the eye. Although the emission power of the laser tube of the scanner in the supermarket is very small, perhaps only a few microwatts, due to the imaging effect of the eyes, this energy will damage the photoreceptor nerve on the retina, which will seriously cause permanent damage.
Therefore, if the laser irradiates the eyes when scanning the goods, it may cause harm to the eyes. It is recommended that you try to avoid direct laser irradiation on your eyes when scanning goods to protect your eyesight health.