Photometry in the workplace: the rationale for a new method.

Area of Science:

• Occupational health
• Lighting engineering
• Visual ergonomics

Background:

• Workplace lighting assessment traditionally relies on illuminance measurements.
• Illuminance may not adequately represent the light experienced during near work tasks.
• A new approach is needed to evaluate lighting conditions in detail for specific work situations.

Purpose of the Study:

• To describe a novel method for evaluating natural and artificial light in near work.
• To assess the role of luminance measurement in understanding workplace lighting.
• To provide a more accurate method for evaluating visual conditions in offices.

Main Methods:

• The method involves identifying visual targets, defining the visual field, measuring luminance, and creating iso-luminance maps.
• Luminance measurements pinpoint primary and secondary light sources within the visual field.
• Luminance ratios are calculated and compared for analysis.

Main Results:

• Illuminance measurements were found to be inadequate for evaluating near work lighting.
• Luxmeters integrate light over a wide angle, which is not representative of the focused visual input during near work.
• The operator's retina is primarily stimulated by light from objects within the occupational visual field.

Conclusions:

• Detailed luminance measurement in the occupational visual field aligns with visual physiology.
• This method can aid in risk assessment for visual disturbances.
• It provides a rational basis for optimizing workstation lighting.