Why do we blink when a hammer strikes metal?

Blinking, apart from cleaning and lubricating the soft tissues of eyes, also serves as a protective way of keeping things away from entering the eyes, by lowering the eyelids and lashes for protection. Blinking is a reflex action and happens automatically, as soon as the brain perceives a threat. The striking of hammer is taken as a threat by the brain. There are multiple muscles that control the reflex action of blinking.