Light ergonomics is the relationship between the light source and the individual."The Ergonomics of Light" by Bradford J. Powell, Buildings.com, October, 2002, retrieved November 3, 2007 Poor light can be divided into the following:
Individual or socio-cultural expectations Insufficient light Poor distribution of light Improper contrast Glare Flicker Thermal heating (over or under) Acoustic noise (especially fluorescents) Color spectrum (full-spectrum light, color temperature, etc.)
Effects of poor light The effects of poor light can include the following: low productivity high human error rates inability to match or select correct colors eyestrain headache a reduction in mental alertness general malaise low employee morale
{| class="wikitable" |- style="height:35px" ! colspan="2" | Recommended Illumination LevelsIlluminating Engineering Society of North America. RIESNA Lighting Handbook. (9th ed.). Illuminating Engineering Society of North America. . |- style="height:35px" align="center" ! Type of Activity !! Ranges of Illuminations (Lux) |- | Public spaces with dark surroundings || align="center" | 30 |- | Simple orientation for short temporary visits || align="center" | 50 |- | Working spaces where visual tasks are only occasionally performed || align="center" | 100 |- | Performance of visual tasks of high contrast or large scale || align="center" | 300 |- | Performance of visual tasks of medium contrast or small size || align="center" | 500 |- | Performance of visual tasks of low contrast or very small size || align="center" | 1000 |- | Performance of visual tasks near threshold of person's ability to recognize an image || align="center" | 3000-10000
Types of light sources {| class="wikitable" |- style="height:35px" ! colspan="5" | Light Bulbs"Lighting Ergonomics - General" by Canadian Centre for Occupational Health & Safety, CCOHS, January, 2003, retrieved November 3, 2007 |- style="height:35px" align="center" ! Type !! Common Application !! Efficiency !! Colour Rendering !! Fog-Smog Penetration |- | Incandescent || Homes || Poor || Good |- | Fluorescent || Home&Office || Good || Fair to good |- | Mercury || Factories, offices || Fair || Fair to moderate |- | Low pressure sodium || Roadway || Good || Poor || Good |- | High pressure sodium || Factories, commercial || Good || Fair to good|| Good |- | Metal Halide || Factories, commercial || Good || Good |- | Light-emitting diode (LED) || Home & office, commercial, industrial || Excellent|| Good
See also Ergonomics Full-spectrum light Artificial sunlight
References