Simply it is a visual impression caused by extreme and uncontrolled brightness.
Generally, Glare is difficulty in seeing in the presence of bright light such as direct or reflected sunlight or artificial light such as car headlamps at night. Because of this, some cars include mirrors with automatic anti-glare functions.
Must Read: Difference Between Luminance and Illuminance?
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In other words, it is a condition of vision in which there is discomfort or a reduction in the ability to see significant object or both due to unsuitable distribution or range of luminance or due to extreme contrasts in space and time.
Glare can be generally divided into two types, Discomfort glare and Disability glare. Discomfort glare results in a natural desire to look away from a bright light source or difficulty in seeing a task. Disability glare harm or disable the vision of objects without necessarily causing discomfort.
Classification of Glare:
Simply it is a visual impression caused by extreme and uncontrolled brightness.
Based on Source of Nature:
- Direct Glare
- Reflected Glare
- Veiling Glare
Based on its Impact on Vision:
- Discomfort Glare
- Disability Glare
How Glare is Occurred or Produced:
Excessive contrast or abrupt and large changes in brightness produce the effect of glare.
When glare is present, the efficiency of vision is reduced and small details or subtle changes in scene cannot be perceived by human eye.
It may be:
01. Direct glare due to light sources within the field of vision,
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02. Reflected glare due to reflections from light sources or surfaces of excessive brightness, and
03. Veiling glare where the peripheral field is comparatively very bright.
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Reflected Glare:
Generally it is the variety of ill effects on visual efficiency and discomfort produced by unwanted reflections in and around the task area.
In other words, indirect (reflected) glare is caused by light that is reflected to the eye from surfaces that are in the field of view often in the task area.
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Reflected glare shows up on the task itself, such as a computer screen as shown in image:
Also Read: All You Need to Know About Day Light
Best Ways to Minimize Outside Glare Entering a Room:
Glare can be minimized either by Shielding the open sky from:
01. Direct sight by louvers,
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02. External hoods or deep reveals,
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03. Curtains or other shading devices or
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Window Curtains
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Window Shading Device
04. By cross lighting the surroundings to a comparable level.
A gradual transition of brightness from one portion to the other within the field of vision always avoids or minimizes the glare discomfort.
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