The fraction of solar radiation in the visible light spectrum that passes through the fenestration.
The ratio of the amount of total visible solar energy (380-780 nanometers) that is allowed to pass through a glazing system to the amount of visible solar energy falling on the glazing system. Value is usually expressed as a percent. Glare is influenced by visible light through a glazing system.
The percentage of visible light (390 to 770 nanometers) within the solar spectrum that is transmitted through glass.