Eyelids—Intermittent Wipers

Engineer and inventor Robert Kearns (1927–2005) lived near Detroit, the hub of America’s auto industry. While driving across town one rainy day, Kearns was bothered as his wipers scraped and vibrated across his semi-dry windshield. The misty rain was too heavy for him to drive with his wipers off but too light to leave them on. At that time, most windshield wipers offered just two settings, one for normal rain and the other for heavy downpours. Neither speed fit his situation.

Kearns also had only one good eye, and the smearing motion of the wipers did not help. What happened next was an insight that changed Kearns’s life.

Annoyed by the wipers chattering across his semi-dry windshield, Kearns asked himself whether windshield wipers could mimic the blinking of our eyes.

He simply asked himself whether windshield wipers could mimic the blinking of our eyes. That is, could the wipers be programmed to operate intermittently when the rain is light? This irregular speed would slow down and quiet the wipers, while it still cleared the windshield and avoided the hypnotizing effect of the other settings.

Back home, Kearns tinkered with wiper motors until they could work at intervals. This adjustment was a technical challenge because he did not have the compact integrated circuits that we have today.

When he demonstrated the off-and-on wiper behavior to auto engineers, they initially thought he must be using a hidden switch. But he was clearly on to something. In 1964 he patented the first intermittent windshield wiper with an adjustable delay.

Unfortunately, his effort initiated a string of legal battles with major car makers who developed similar features. His patent infringement lawsuits reached the U.S. Supreme Court, and he eventually won millions of dollars, but at the cost of his job, his marriage, and his mental health. The 2008 film Flash of Genius tells the story of Robert Kearns and his invention.

The blinking of our eyes is automatic and essential. Its saline washer fluid moistens and protects the outer cornea of the eye while removing dust. Other protective features include our eyebrow “umbrellas” and recessed eyeball sockets.

The average eye blinks one to two times each minute for infants and ten times faster for adults. This blinking adds up to nearly 500 million blinks over an average lifetime. The actual mechanism, however, is not well understood. It may involve a “blinking center” in the brain.

Today billions of windshield wipers duplicate the eye’s intermittent blinking. Yet none last as long or work as efficiently as our God-given eyelids. Proclaiming the wonders of God’s handiwork in creating the human body, the psalmist asks us to think about their source, “He who planted the ear, shall He not hear? He who formed the eye, shall He not see?” (Psalm 94:9).