Fifteen to twenty foot candles is the accepted minimum light required for satisfactory vision.health and fitness Updated: Jun 02, 2003 21:04 IST
Have sufficient light: There should be enough light to enable us to see details of objects and surroundings without strain. Fifteen to twenty foot candles is the accepted minimum light required for satisfactory vision.
Distribution should be even: Light of the same intensity is required over the whole field of work. Proper dispersal of light, without shadows is required for efficient vision.
Avoid glare: Glare is excessive contrast. This causes annoyance and reduces critical vision. Automobile headlights at night give off such a glare that pedestrians feel discomfort and are unable to adjust visually to the surroundings in the presence of glare.
The disappearance of trees from roadsides, and the increase of glass fronted buildings, has increased the glare factor on roads. The same happens with polished floors, tabletops, or mirrors in houses. When direct rays of sunlight from windows or doors hit these surfaces, they give off a discomforting glare.
Avoid shadows: Shadows are inevitable. But too many sharp shadows confuse vision.
No flickers, please: The light should be steady. Flickering causes eye strain.
Opt for lights of the colour of natural light. The colour of light is not as important as the intensity. But since natural light has a soothing effect on us, the closer the colour is to natural light, the better it is for us. The background, usually walls and ceilings, should be of lighter colours and the floor, darker.