What is the Difference Between Glare, Light Spill and Light Trespass?

Glare is excessive brightness that causes visual discomfort and reduces visibility. It often occurs when a light source is too bright or poorly directed, making it difficult for pedestrians, drivers, or nearby residents to see clearly. Controlling glare improves safety and visual comfort.

What is light spill?

Light spill occurs when artificial light extends beyond the intended area being illuminated. For example, street lights may cast light onto nearby buildings, gardens, or open spaces that do not require illumination. Light spill contributes to energy waste and environmental light pollution.

What is light trespass?

Light trespass happens when unwanted artificial light enters private properties, such as through bedroom windows or into residential gardens. It is a common cause of complaints about outdoor lighting and can often be reduced using light spill shields and improved fixture design.