It "blings" my eyes.

Light is very important for human vision. To deal with the limitation of eyes to see in the dark, artificial light is invented.  The lighting improves our physiological performance of vision to detect, perceive and distinguish the existence, size, shape, colour, texture, moving, distance, changes in the brightness or colours, etc. of the objects to be seen. Consequently, the efficiency of the human activities will be increased with the improvement of visual performance.(NARISADA & SCHREUDER, 2004)

What if there is too much lighting than we need?

Light pollution is an unwanted consequence of outdoor lighting and includes such effects as sky glow, light trespass, and glare. (What is light pollution?, 2007)

Figure 1 Useful light vs. light pollution

Source: (What is light pollution?, 2007)

Sky glow:

Sky glow is the result of light that is projected upwards, and then scattered and scattered backby aerosols in the atmosphere to the surface of the Earth. colouring the night sky and reducing the visibility ofastronomical objects.(Mizon, 2002)

Part of the stray light is projected directly upwards due to poorly designed lighting or the light is aimed upwards on purpose. Another major contribution to the stray light is the light that is well-directed to objects, but reflected by them. For example, road surfaces, grass, and buildings reflect a fair amount of the incident light, and the reflected light usually goes upwards.(NARISADA & SCHREUDER, 2004)

Figure 2 Sky glow in Kuala Lumpur, Malaysia

Source: (Morris, 2011)

Light trespass:

Light trespass occurs when spill light is cast where it is not wanted. Light trespass is somewhat subjective because it is difficult to define when, where, and how much light is unwanted. An example of light trespass is when spill light from a streetlight or floodlight enters a window and illuminates an indoor area.(What is light pollution?, 2007)

Figure 3 Light trespass

Source: (LIGHT POLLUTION)

Figure 4 Spill light illuminates the bedroom through window

Source: (The City Dark, 2011)

Glare:

Glare is a visual the sensation produced by luminance within the visual field that is sufficiently greater than the luminance to which the eyes are adapted to. It is subjective, and sensitivity to glare can vary widely. Older people are usually more sensitive to glare due to the aging characteristics of the eye. Disability glare is the reduction in visibility caused by intense light sources in the field of view, while discomfort glare is the sensation of annoyance or even pain induced by overly bright sources. (What is light pollution?, 2007)

Figure 5 Glare

Source: (Rensselaer Polytechnic Institute, 2007)

Effects of light pollution:

Health:

Light pollution is a form of annoyance. According to the World Health Organization, annoyance is described as a feeling of displeasure associated with any agent or condition believed to affect adversely an individual or a group". Annoyance can lead to stress. It depends on the stress level whether the health will be influenced.(NARISADA & SCHREUDER, 2004)

Light pollution is also investigated as a interfering, aggravating factor that suppresses natural melatonin levels in humans at night. This suppression simply pulls out the stops to cancer cell growth. The hormone melatonin normally impedes cancer cell growth and can even cause cancer cell death. (How Light Pollution Affects Human Health)

Animal:

Studies have shown that many animals, like insects and birds, suffer from light at night. Insects are attracted by light. The many insects may attract predators and, in their tum, secondary predators. "Street lighting is on the one hand favorable for predators. Lighting may, however, cause unnatural death"(NARISADA & SCHREUDER, 2004)

Bright lights nearby the beach discourage females from coming ashore to nest. But more important, hatchlings can become disoriented by manmade lighting and fail to find their way quickly to the relative safety of the open sea. The newly hatched sea turtles developed instincts to frenetically crawl toward the lightest horizon, because the ocean breakers would reflect starlight. In the past 100 years, the lighting situation has changed dramatically. Instead of heading directly into the sea, hatchlings go toward the brighter light. Those that wander in circles on the sand have a much higher risk of dying of dehydration, exhaustion or predation. (Hutchinson)

Figure 6 Newly hatched sea turtles wander on the beach

Source: (Hutchinson)

Energy usage, air pollution:

Artificial lighting consumes electricity. We need to burn fossil fuel for the production of electricity, and the by-product of electricity is pollutants. The pollutants include greenhouse gases and toxic chemical that leads to environmental problems such as global warming and they threaten human health. Why do we need to spend money on excess lighting to bring harm to the environment and ourselves?

Safety:

Light can cause confusion or visual distraction that threatens road safety. High levels of glare can also decrease visibility for the road user and increase the risk of road accident.Some of the households over lit their homes to be “safer”. However, overly bright lighting creates a sharp contrast between light and darkness, making the places outside the area of illumination nearly invisible. Bad lighting can even attract criminals by creating deep shadows that offer concealment. (Design Out Crime, 2010)

Figure 7 Security lighting which creates deep contrast. Can you spot the person in the left picture?

Source: (Smit)

Colourful lighting may create beautiful night view. What about the plumes emit from chimney during energy production?

Figure 8 Emission from energy production

Source: (Jones, 2014)

Works Cited

Design Out Crime. (2010, December). Retrieved September 20, 2014, from International Dark-Sky Association: http://www.darksky.org/assets/documents/ida_safety_brochure-bw.pdf

How Light Pollution Affects Human Health. (n.d.). Retrieved September 20, 2014, from Department of Physics, Florida Atlantic University: http://physics.fau.edu/observatory/lightpol-health.html

Hutchinson, L. I. (n.d.). TURNING NIGHT INTO DAY: LIGHT POLLUTION’S IMPACTS ON WILDLIFE. Retrieved September 20, 2014, from Lighting.com: http://lighting.com/light-pollution-wildlife/

Jones, B. (2014, March 13). Energy, Climate Change and Security in the Context of Ukraine: A Discussion with Danish Foreign Minister Martin Lidegaard. Retrieved September 20, 2014, from BROOKINGS: http://www.brookings.edu/blogs/planetpolicy/posts/2014/05/13-lidegaard-europe-energy-ukraine

LIGHT POLLUTION. (n.d.). Retrieved September 20, 2014, from Starlight Theatre: http://www.starlight-theatre.ca/LT-POLLUTION.HTM

Mizon, B. (2002). Light pollution: responses and remedies. London: Springer.

Morris, E. (2011, February 21). Light Pollution in the World. Retrieved September 20, 2014, from Light Pollution and Dark Skies: http://lightpollutionanddarkskies.blogspot.sg/

NARISADA , K., & SCHREUDER, D. (2004). LIGHT POLLUTION HANDBOOK. Netherlands: Springer.

Rensselaer Polytechnic Institute. (2007, February). What is glare? Retrieved September 27, 2014, from Lighting Research Center: http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/glare.asp

Smit, J. (n.d.). Light Pollution—the dark side of light. Retrieved September 20, 2014, from PRETORIA CENTRE OF THE ASTRONOMICAL SOCIETY OF SOUTHERN AFRICA: http://www.pretoria-astronomy.co.za/light_pollution.htm

The City Dark. (2011, August 17). Retrieved September 20, 2014, from Urban Omnibus: http://urbanomnibus.net/2011/08/the-city-dark/

The Woman’s Guide to Buying Flattering Eyewear: When should I Buy New Glasses? (2014, February 13). Retrieved September 20, 2014, from Avoce Eyewear Blog: http://avoceeyewear.com/wp/?p=375

What is light pollution? (2007, February). Retrieved September 20, 2014, from Lighting Research Center: http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/lightPollution.asp