The intended purpose of sunglasses is to protect our eyes from being blinded by the sun. But for most people sunglasses are more about fashion and lifestyle than about functionality.
By augmenting ordinary sunglasses with a photoresistor and two "High-Power_LEDs" they can be transformed into an ironic persuasive artifact. They can now only be used to their intended purpose.
In the dark these sunglasses blind you. In sunlight they protect you from being blinded.