Light is one of the most powerful tools in shaping mood, atmosphere and activation – guiding movement, creating safety, and defining how a space is experienced after dark. As designers, we rely on it instinctively, yet the overuse of artificial light at night can disrupt ecosystems, diminish human wellbeing, and erase our connection to natural darkness. The challenge is not to remove light, but to use it more thoughtfully – balancing function and experience with environmental responsibility.