What does glare refer to in terms of lighting?

Glare in terms of lighting predominantly refers to the discomfort or difficulties in seeing that arise from excessive brightness or intensity of light, which is well captured by the second option. This bright light creates a visual challenge and can hinder people's ability to see properly in environments like sports facilities. Specifically, glare can be categorized into two types: discomfort glare, which refers to the irritating light levels that can distract or annoy individuals, and disability glare, which can temporarily impair vision.

The option about light being directed or reflected upward and wasted touches on the concept of inefficient lighting but doesn’t accurately define glare itself. Glare is more about the discomfort caused by intense light rather than the management of light direction or waste. Therefore, understanding glare is crucial for sport facility managers when designing lighting for areas such as playing fields or spectator areas, ensuring that lighting levels are appropriate to balance visibility with comfort.