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Light and vision

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light and vision

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Light and vision

  2. 2. INTRODUCTION  All activities of human life depends on the light that exists in their environment .  According to Statistics Annual Report Perkeso 2003, 7,940 number of treachery cases due to the eyes , ears , mouth and nose.  Level of comfort and worker satisfaction depends on the quality of ventilation, lighting , acoustics and other aspects of the environment of the workstation ( Tarcan et al . , 2004) 2
  3. 3. LIGHT AND VISION  Light affects humans in at least two ways:  It enables us to see  It regulates our bodies' rhythms such as the sleep/wake cycle.  Different types and levels of light can affect a person's ability  To see clearly,  Identify people and objectsdrive safely. It can also increase sleep efficiency of older adults and reduce symptoms of seasonal affective disorder, or SAD, felt by many people during winter months. 3
  4. 4. LIGHTING  Light is the power source from sun, lamp and other else which allows an object can be seen.  Light have vary of wavelength in visible spectrum which is about 380µm to 780µm.  Normal human eye can receive wavelength of visible spectrum light around 400µm to 700µm.  Lighting is an essential provision for any workplace. 4
  5. 5.  It is preferable to provide uniform illumination over the entire workplace by combining both natural and artificial lighting.  Light that illuminates the work area is caused by the electric light.  A comfortable lighting level is needed in jobs that require precise vision and focus. 5
  6. 6.  Good lighting helps us to see and to recognize hazards.  It can reduce visual strain and discomfort.  Poor lighting may affect workers performance and health as poor visibility increases the chances of errors being made. 6
  7. 7. TYPES OF LIGHTING 7 General lighting provides fairly uniform lighting. An example would be ceiling fixtures that light up large areas. Localized-general lighting uses overhead fixtures in addition to ceiling fixtures to increase lighting levels for particular tasks. GENERAL LOCALIZED - GENERAL
  8. 8. 8 Local (or task) lighting increases light levels over the work and immediate surroundings. Local lighting often allows the user to adjust and control lighting and provides flexibility for each user. LOCAL (OR TASK)
  9. 9. LIGHT DISTRIBUTION CLASSIFICATION 9 Classification Luminaire Upper- hemisphere flux Lower- hemisphere flux
  10. 10. TYPES OF LIGHT EXPOSURE  Working Exposure  The exposure that was received at work place due to the unresponsible situation of the operation management.  Exposure towards radon and types of works that related to the prevention of radionuclide material in the small quantity is not consider as working exposure unless been stated by the authorities. 10
  11. 11.  Medical Exposure  This exposure is reserved for those that undergoes diagnosis and medical treatment and those who in the context of assisting patients that undergoes diagnosis and medical treatment.  Parents are always advised to hold and handle their children while doing x-ray. 11
  12. 12.  Public Exposure  Else than included in the medical and working exposure  In light protection management, only working protection and exposure is take into concern.  The harm from the medical exposure must be ensured by the medical practioner and the patients must not receive and limits the light exposure not more than yearly dosage. 12
  13. 13. FACTORS AFFECTING LIGHTING  Design of lighting system  This factor affect the spread of light throughout the space. A good design can avoid the corner or space that is dark.  Light distribution  The distribution of light that is not uniform into the room will raises the dark corner and space. 13
  14. 14.  Light reflection  The reflection of light is depends on the color and finishing.  Space area  The wide area is more efficient in utilize the lighting than the small area. 14
  15. 15. SIGNS OF POOR LIGHTING  Difficulty seeing document or screen (too much light or glare, or too little light or shadows)  Eyestrain,  Eye irritation,  Blurred vision,  Dry burning eyes, and  Headaches.  Computer Vision Syndrome 15
  16. 16. LIGHTING EFFECTS ON HEALTH  The blue component of electromagnetic spectrum can harm the retina but this is only caused by accidental exposure to sunlight or to very high intensity artificial lights so it is rare.  Exposure to light at night while awake, such as in shift work, or light in late evening or early morning may be associated with an increased risk of breast cancer and also cause sleep, gastrointestinal, mood and cardiovascular disorders.  Light itself has an effect on alertness, sleep, mood and the circadian rhythms regardless of the type of lamp used. 16
  17. 17. LIGHT PROTECTION SYSTEM  Consist of two light protection. These systems is divided based on the working condition. The two systems are :  Suggested practice and currently on going practice  Intervention 17
  18. 18.  This light protection system is applied on normal working condition .  In this working condition, light protection system principle consider all the works should be put in this priority :  Application justification  Application optimization  Comply with individual dosage limit and risk dosage. 18 SUGGESTED AND ON GOING PRACTICE
  19. 19. INTERVENTION  Is the action that is taken in exceptional circumstances such accidents and emergency.  Intervention must give a better results than without the intervention.  For the application of justification, intervention made based on the disaster and cost of intervention.  Shape, scale, duration of intervention should be optimum, so the profit from dose reduction can be maximum. 19
  20. 20. LIGHT PROTECTION OBJECTIVES  Protect human and its surrounding from unwanted light exposure and received the benefits of light.  Prevent side effects of no stochastic and limits the stochastic effects from the light exposure 20
  21. 21. LIGHT PROTECTION PRINCIPLE SYSTEM  Light protection principle system emphasize on prevention and light hazard control with :  Get rid of or minimize mengion light risk  Hazard control  Employees control. 21
  22. 22. VISION  Ability to interpret information from the optical light to the eyes.  Many parts of physiological involve in vision is referred collectively as the visual system.  Studies have found that majority individuals who work at a computer experience eye-related discomfort and /or visual problems. 22
  23. 23. FACTORS OF AFFECTING VISION  Object dimension  Small object need more concentration by eye than the large object.  Duration of observation  The longer the time is taken to focus an object, the more better the vision to focus.  Age of worker  Aged workers have limited visibility in observing object. 23
  24. 24.  Object color  Color brightness because of the reflection of light  State of worker vision  Poor computer design  Workplace ergonomics  Highly demanding visual task 24
  25. 25. GOOD VISUAL ENVIRONMENT  Have sufficient light, coming from the right direction and not cause obscuring shadows  Provide good (but not excessive) contrast between the task and the background  Limit glare and extreme contrasts  Provide the right type of light. 25
  26. 26. NON-VISUAL EFFECTS OF POOR LIGHTING  When people are exposed to glare or have uncorrected vision problems, they tend to lean forward or backward in an attempt to compensate.  An awkward body position leads to eye strain and accelerates postural fatigue  In turn, it contributes to musculoskeletal injuries (MSI). 26
  27. 27.  Musculoskeletal injury (MSI) is an injury or disorder of the muscles, tendons, ligaments, joints, nerves, blood vessels or related soft tissue including a sprain, strain and inflammation, that may be caused or aggravated by work. 27
  28. 28. PREVENTION TO EYESIGHT PROBLEM  Most jobs now a days were carried out using a computer cause the user receive light and excessive glare from the screen monitor. As prevention:  Make sure there are plenty of light brighten the office without many shadows on desk  Reduce brightness level of screen monitor  Put the finishing on the office window as wood blinds or vertical blinds if there be sunlight that directly into the computer.  Use the protection goggle when doing a job that involve of lighting (eg. Welding) 28
  29. 29. ACT RELATED TO LIGHTING  Laws of Malaysia, Factories and Machinery Act 1967 (Act 139)  Part II (Safety, Health and Welfare), Section 22 (provisions relating to health), Subsection 1 (e) (i). An effective provision shall be made for securing and maintaining sufficient and suitable lighting, whether in natural or artificial, to every part of factory which where the person are working or passing; 29
  30. 30.  Part II (Safety, Health and Welfare), Section 22 (provisions relating to health), Subsection 1 (e) (ii).  The minister may prescribe a standard that adequate and suitable lighting for factory or for any class or description of factory or its part or any process; 30
  31. 31. MALAYSIAN STANDARD FOR LIGHTING IN WORK PLACE  Guidelines on Safety and Occupational Health in Office 1996 (DOSH)  The background lighting for the office is 200 lux  Routine place of daily office work is 100 lux  Work place with reading space and bad eyesight is 600 lux 31
  32. 32. CONCLUSION Lighting is one of most significant environmental factors that affect the visibility of workers and quality of work at the workplace. Therefore, it is important for organizations to ensure appropriate environment with individuals who will perform the task. 32
  33. 33. REFERENCES Muhammad Muhammad Isa and Huda Zainuddin. (2014). International Journal of Business, Humanities and Technology. Effect of Human and Technology Interaction: Computer Vision Syndrome among Administrative Staff in a Public University, Vol. 4 (No. 3), 39-44. Persuruhjaya Penyemak Undang-Undang Malaysia. (2006). Undang-undang Semula. Akta Kilang dan Jentera 1967 (Akta 139). Tuan Haji Abd. Hamid bin Osman. (2014). Info sihat bahagian kesihatan persekitaran jabatan kerajaan tempatan: Fungsi dan Faktor Ergonomik di Pejabat. Baharudin Mastari. (2011). Panduan Pengurusan Persekitaran, Keselamatan dan Kesihatan Pekerjaan (OSHE). 33