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What is the critical zone for direct glare?

  1. Area behind the observer

  2. Directly below light fixtures

  3. Area above 45 degrees from the light source

  4. Space immediately adjacent to windows

The correct answer is: Area above 45 degrees from the light source

The critical zone for direct glare is recognized as the area above 45 degrees from the light source. This is because glare occurs when a light source is too bright or is positioned in such a way that it interferes with the observer's ability to see properly. When lighting is positioned above the line of sight at an angle greater than 45 degrees, it creates a greater likelihood of perceived blinding or discomfort from the light source. Proper lighting design takes these angles into account to minimize discomfort and enhance visual comfort, ensuring that spaces are not only functional but also pleasant to inhabit. By controlling the placement of lighting fixtures and the intensity of light they emit, designers can reduce potential glare that can impact a person's visual performance and overall comfort in a space.