They use Class 1 Lasers which are safe for the eyes.
Class 1 lasers are products where the irradiance (measured in watts per metre square) of the accessible laser beam (the accessible emission) does not exceed the Maximum Permissible Exposure (MPE) value. Therefore, for Class 1 laser products the output power is below the level at which it is believed eye damage will occur. Exposure to the beam of a Class 1 laser will not result in eye injury and may therefore be considered safe. However, some Class 1 laser products may contain laser systems of a higher class but there are adequate engineering control measures to ensure that access to the beam is not reasonably likely. Examples of such products include laser printers and compact disc players. Anyone who dismantles a Class 1 laser product that contains a higher class laser system is potentially at risk of exposure to a hazardous laser beam. A laser that is inherently safe and cannot exceed the MPE under any circumstances is exempt from the classification system.
The eyes natural blink reflex is enough to protect you.