Health Hygiene & Sanitation

Lesson 16 : Lighting And Noise

Factors Required For Efficient Vision

• Sufficiency:


• Lighting should be sufficient to help to distinguish the objects and the surroundings without eye strain
• Minimum required is 15 to 20 foot candles
• Distribution:
• It should be uniform, with equal intensity all over the fields


• Absence of glare:


• Glare is excessive contrast
• Glare causes annoyance, discomfort and reduces critical vision


• Absence of sharp shadows: Though light shadows are inevitable, sharp shadows do the same effect as glare


• Steadiness: source of light should be constant, not flickering


• Color of light:


• If intensity is adequate, color of light has no problem on vision.
• However, light of color nearer to natural light can be soothing


• Surroundings:


• Should reflect enough light to help recognition of objects from their surrounding