Light ergonomics
Light ergonomics is the relationship between the light source and the individual.[http://www.buildings.com/articles/detail.aspx?contentID=1070 "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. {{ISBN|0-87995-150-8}}. | |
| 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[http://www.ccohs.ca/oshanswers/ergonomics/lighting_general.html "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 |