Provide visual comfort and enhance acuity for all users through electric lighting.
This WELL feature requires projects to provide appropriate illuminances on work planes for regular users of all age groups while taking into account light levels required for the tasks performed in the space.
Humans perceive the world through visual cues that are received through images formed on the retina of the eye. The light levels in a space can enhance the user’s ability to perform tasks in that space while contributing to the feeling of spaciousness. The age of the individual is also a factor in the amount of light required for visual acuity. As humans age, the transmission of light through their lenses is reduced. This is due to age-related changes including increased light absorption by the lenses , smaller pupil size, increased scattering of light due to thicker lenses and yellowing of the lenses. This aging of the eye indicates that an increase in light levels is required to ensure visual acuity.
While developing a lighting strategy to accommodate the visual acuity of users, it is critical to take into account the tasks conducted as well as the age of the users. Projects may refer to published recommendations by lighting associations or authorities on using electric lighting design strategies for light levels required on the work plane. Lighting recommendations published by authorities provide a range of lighting levels for different age groups and tasks.
Visual abilities of individuals are dependent on the properties of the lighting environment and the light entering the eye. Visibility and the ability to perform a task require a minimum threshold of illuminance, which may be achieved by incorporating electric lighting with adequate daylighting strategies.
Light Levels for Visual Acuity
Verified by Performance Test, Design Specifications
For All Spaces
The following requirements are met:
All indoor and outdoor spaces (including transition areas) comply with illuminance recommendations specified in one of the following lighting reference guidelines:
- IES Lighting Handbook 10th Edition or IES Lighting Library.
- EN 12464-1: 2011.
- ISO 8995-1:2002(E) (CIE S 008/E:2001).
A lighting plan details the below:
- Tasks or activities considered for visual lighting design in the project. All tasks and activities regularly undertaken by occupants are considered.
- Height of work plane or other target of illumination.
- Age ranges for the majority of occupants.
Note: Design specifications should include the reference guideline used, illumination levels achieved, height of work plane or target of illumination, tasks/applications considered and age groups of occupants.
© International WELL Building Institute
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