Page 187 - The Power of Light, Colour and Sound for Health and Wellness draft

Texture of light
The spread and direction of the light gives a lot of textural information. Glossy shines or progressive shades will tell about surface and grain and fnish – the eyes will expertly and swiftly compare a lot of optical data. Sensibly directed lightbeams give distinct contrasts to accentuate structural physical detail. Dark interiors need lots of light to set off important features while light surfaces only need a delicate touch to highlight the obvious. We are biologically conditioned to observe the world in light coming from above with shadows cast sideways or on the ground. Beams coming from below may have some theatrical value but are generally disturbing and upset our natural input of information.
Shadows of light
Our impressions of light really depend on the depth of the shadows generated and how they fall. Shady constellations can vary infnitely but a detailed play of silhouettes will tell a lot about depth and relief and background. This three-dimensional information is mandatory in precision work like fne sowing or electronic soldering. A more familiar example is the recognition of faces where the light ideally should slant from above to faithfully model the features.
Utility of light
An ergonomic and functional lighting design will frst of all emphasize excellent visual conditions to enable continuous and exacting work. Adults spend most of their awake time performing different forms of precision jobs that are most taxing on the visual system. When objects are distinctly separate and clearly conspicuous the eyes will feel at ease even during demanding tasks. Disturbing shadows or light refexes must systematically be eliminated. The visual sense is biologically an extension of manual touch and good ergonomic lighting will help the smooth coordination of eyes and hands. The human organism is not ideally adapted to work in minute detail but by distributing the illumination in meaningful directions modern monkeys can perform technical work reasonably well.
Refexes of light
Shimmering refections and shiny gloss indicate smooth surfaces characteristics. The refective properties are quite pronounced and light sources must be positioned with care. Abrupt changes are most disturbing
185