Sunday, March 16, 2008

INTRODUCTION TO LIGHT POLLUTION II - glare

As a continuation to our previous post:


We proudly present:

*GLARE* (- . -)

Often after a bright camera flashes in your eye, do you feel this uncomfortable sensation, where your eyes is trying to recover from that blotches of dark areas in your vision? That is a result of BLINDING GLARE!

Glare is usually the result of excessive contrast between bright and dark areas in the field of view. For example, glare can be associated with directly viewing the filament of an unshielded or badly shielded light. Light shining into the eyes of pedestrians and drivers can obscure night vision for up to an hour after exposure. Caused by high contrast between light and dark areas, glare can also make it difficult for the human eye to adjust to the differences in brightness.

Glare is particularly an issue in road safety, as bright and/or badly shielded lights around roads may contribute to accidents as it might unexpectedly, partially blind drivers and pedestrians.

Glare can also result in reduced contrast, due to light scattering in the eye by excessive brightness, or to reflection of light from dark areas in the field of vision, with luminance similar to the background luminance. This kind of glare is a particular instance of disability glare, called veiling glare.

Glare can be categorized into different types. One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies. According to this classification:

Blinding Glare describes effects such as that caused by staring into the Sun. It is completely blinding and leaves temporary or permanent vision deficiencies.

Disability Glare describes effects such as being blinded by an oncoming cars lights, or light scattering in fog or in the eye reduces contrast, as well as reflections from print and other dark areas that render them bright, with significant reduction in sight capabilities.




Discomfort Glare does not typically cause a dangerous situation in itself, and is annoying and irritating at best. It can potentially cause fatigue if experienced over extended periods, and lead to more serious depression, lethargy, mentally-stressful disorders.


Due to our uploader's LIMITED tech-savvy capability, the pictures turned out like that. (look upwards) SORRY! x(