Hemin Johnson BGI Lighting Lighting is essential for

Hemin Johnson BGI

Lighting • Lighting is essential for efficient vision. • If the lighting conditions are Not ideal the visual apparatus is to put to strain which may lead to General fatigue and loss of efficiency. • Imperfect light is one of the causes of ill health and accidents. • Good lighting in houses, schools, factories, offices or any work area is essential for efficient vision. • Inadequate light may cause damage to eyes and produce physical and mental discomfort.

Factors essential for lighting • Sufficiency – The light should be sufficient. • Distribution – distribution of light in any place should be uniform. • Absence of glare – glare creates acute discomfort and reduces the critical vision. • Absence of sharp shadows – slight shadows are Unavoidable, but sharp and contrasting shadows are distributing. • Steadiness - the light should be constant, flickering causes eye strain and may lead to accidents. • Colour of light – very bright flashing colours may harm our eyes and would cause discomfort.

Types of lighting 1. Natural lighting – natural lighting is derived partly from the visible sky and partly from reflection. It also depends upon time of the day, season, weather, and atmospheric pollution. This can be obtained by effectively location and place of building. 2. Artificial lighting – artificial lighting should be close as possible to day light in composition. Artificial lighting needs consistency, uniformity, and adequacy. Some common examples are candles, oil lamps, gas light, and electric lighting.

Requirements for good lighting • • Lighting, natural or artificial, has to be good. Good lighting promotes good vision to workers. Very bright flashing colours should be avoided. Glare should be prevented since glare creates acute discomfort. Distribution of light in any place should be uniform. Light should be constant, flickering cause eye strain. Good lighting needs consistency, uniformity And adequacy.

Measurements of lighting Light is measured for the amount and for intensity by the standard. Candle power is the standard measurement of artificial lighting. • Luminous intensity – it is the power of a light source considered as a point radiating in all directions. • Luminous flux – it is a flow of light related to a unit of solid angle, and is measured in lumens. • Illumination – it is the amount of light reaching a surface measured in lux per unit area.

Effects of light on health • Good light promotes good vision to the workers. • The eyes of the workers can be protected by means of goggles, to avoid excess of light in welding process. • Light Impacts human Health and performance by enabling Performance Of visual tasks. • Artificial light at night Can negatively Affect human health Increasing risks For sleep disorders, Obesity, depression Etc. • Effects on mood anxiety. • Increase headaches, Fatigues, and stress levels.

Questions � 1. What is lightning? 2. Types of lighting? 3. Enlist the requirements for good lighting?