Why should you never look directly at an active transceiver port or the end of a fiber cable?

Looking directly at an active transceiver port or the end of a fiber cable is dangerous primarily due to the intense light that can be emitted from the fiber optics. This light, often in the near-infrared spectrum, is not visible to the naked eye and can cause harm to the eyes if directly observed. The light can be powerful enough to potentially burn the retina, leading to permanent eye damage.

While concerns about physical damage to the cable, ensuring proper signal transmission, and maintaining equipment integrity are important in the context of network operations, they do not pertain to the immediate and serious risk of direct eye exposure to the light from active fiber optic cables. For safety, it is critical to adhere to proper handling guidelines, which include never looking directly at an active fiber optic connection.