The Joo Janta 200 Super-Chromatic Peril Sensitive Sunglasses have been designed to help people develop a relaxed attitude to danger. They follow the principle “what you don’t know can’t hurt you” and turn completely dark and opaque at the first sign of danger. This prevents you from seeing anything that might alarm you. This does, however, mean that you see absolutely nothing, including where you’re going.
Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so.