Final answer:
In arc welding, a welder's helmet with a special filter protects the eyes from intense visible light and harmful electromagnetic radiation, preventing damage such as 'welder's flash' and cataracts.
Step-by-step explanation:
In the arc welding process, eye exposure to intense visible light is prevented for the most part by the welder's helmet. The helmet is designed with a special filter to protect the eyes from the high-energy electromagnetic radiation that can be emitted during welding, which includes intense visible light as well as ultraviolet (UV) rays. These rays have the potential to cause serious damage to the eyes, including 'welder's flash' or photo keratitis, and can lead to cataracts. Full coverage eye protection is the best way to safeguard against UV radiation and its harmful effects. Welder's gloves also provide protection from the high thermal energy generated during the welding process, which can be felt even a few meters away and produce light visible for kilometers.