What Is Glare and How Anti-glare Lighting Can Help
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What Is Glare and How Anti-glare Lighting Can Help
Glare is one of the main factors affecting the health of the light environment. Although the human eye can adapt to brightness within a range of about 14 orders of magnitude, after a period of time to adapt to a certain field of view brightness level, our eyes adapt to the effective area of brightness will be reduced to 4 to 5 orders of magnitude, and other objects or light sources higher than this range will cause glare.
What is glare?
Glare is a visual sensation caused by excessive brightness or contrast in the field of view, which can cause discomfort, irritation, or even temporary blindness. It can be caused by direct or reflected light from a bright source, such as the sun, LED lights, or electronic screens. Glare can affect visual clarity, reduce contrast sensitivity, and cause eye strain, headaches, and fatigue. It can also impair depth perception and visual acuity, which can be dangerous in certain situations, such as driving or operating machinery.
What is direct glare?
Direct glare is the light that enters your eyes within your normal field of vision, while the light that is outside of your field of vision will not cause excessive stimulation to your eyes.
What is reflected glare?
Reflecting the light from these lamps through the computer screen causes us to feel glare on the screen or interfere with our viewing of the text on the screen. For example, on the right side, we can see the lamp that is reflected on the screen, but because the brightness of the lamp is relatively low, the light refracted by it will not affect our observation of the text on the screen, while the other light fixture reflected on the right will have a serious impact on our observation on the screen.
Classification of glare and its hazards
According to the way glare is produced, glare can be divided into direct glare and indirect glare.
Direct glare: Glare produced by illuminants present in the field of view, especially in the direction close to the line of sight;
Indirect glare: Even if the light source itself will not be seen by the observer, objects with high reflectivity or glossiness will produce glare as an indirect light source after being illuminated by the light source. Indirect glare can be further divided into reflected glare and glare from light screens.
Depending on the different visual states, glare can be divided into two types: disability glare and discomfort glare.
Disability glare: Causing a certain loss of visual function in the human eye and instantly reducing the human eye’s ability to detect objects;
Discomfort glare: It has not yet affected the visual function, but only caused discomfort in the subjective feeling.
Long-term exposure to glare can cause psychological discomfort and visual fatigue, which in turn can cause physical discomforts such as irritability, inattention, migraines, and eye diseases.
How do you measure glare? And What is UGR?
At present, there are many different models of glare evaluation indicators and methods, and different evaluation algorithms are used according to the specific lighting application environment. For example, threshold increment (TI) is commonly used to evaluate disability glare in road lighting, and unified glare index (UGR) is commonly used to evaluate discomfort glare in indoor workplaces. In addition, there are other indexes for evaluating discomfort glare, such as Glare index (GR), British Glare Index (BGI), CIE Glare Index (CGI), etc. Until recently the most widely used was the Unified Glare Rating (UGR), proposed by Sorensen in 1987 and adopted by the International Commission on Illumination (CIE) in 1995 before being recommended for international application.
UGR is not a value that evaluates the discomfort glare level of a specific set of lighting fixtures. It is a value that characterizes the discomfort glare level of the entire lighting space, calculated through various parameters related to the production of glare.
To give an idea about the recommended UGR value for a given activity, the below table indicates the limiting UGR values for some typical indoor applications. These norms were established by the EN-12464-1.
What is Anti-Glare light?
Anti-glare light is a specially designed light fixture that can minimize or eliminate glare, therefore reducing discomfort, eye strain, and visual impairment. Anti-glare lighting typically uses honeycomb, diffusers, optical lenses, etc., or adopts a special structural design to reduce excessive brightness of the light and achieve a soft light that is comfortable for our eyes.
To create a dynamic light environment, it’s very important to use anti-glare lighting in offices, schools, and hospitals, as glare can accelerate eye strain and reduce work efficiency. Typically, anti-glare lighting meets the requirements of UGR<19. The psychological and physiological tests also confirmed that UGR19 lighting fixtures are highly suitable for mental labor workplaces.
How Anti-Glare lighting can reduce glare?
The honeycomb anti-glare grille can block light from all directions. A honeycomb structure consists of a series of small meshes that are arranged in a hexagonal pattern. When light passes through the meshes, it is diffused and directed in a specific direction, reducing glare and creating a more even lighting effect. It is the easiest to use among all the anti-glare accessories but also has the largest light loss. You’ll need to add more light fixtures in order to meet the high illumination of the environment.
The honeycomb mesh can reduce the direct glare produced by the light source, and the honeycomb mesh can be made so thin that it looks integrated with the lamps, enabling the light suitable for hotel guestrooms, offices, schools, and other commercial settings where glare can be a problem. Honeycomb anti-glare lighting is also used in photography and film production to create a soft, diffused light that is free from harsh shadows and reflections. The commonly used honeycomb anti-glare light fixtures are LED downlights, LED spotlights, Linear pendant lights, etc.
Cross anti-glare grille mainly blocks the light in both vertical and horizontal directions, adjusts the critical position of glare from the edge to the center of the lamp, and increases the shading angle to achieve the purpose of anti-glare. There are several different types of cross anti-glare technologies used in LED lighting, including diffusers made from various materials such as polycarbonate, acrylic, and glass. Some diffusers may also have a special coating or treatment that further enhances their anti-glare properties. Compared to the honeycomb type, the anti-glare effect is not that good, but the luminous flux loss is small and suitable for a variety of applications, including office lighting, outdoor lighting, and hotel lighting, among others.
Shading leaves anti-glare
The shading leaves can block the light from all directions, and it is easy to adjust the light of the luminaire. The anti-glare of shading leaves are usually made of metal, plastic, and other materials. By adjusting the angle and direction of the leaves, we can achieve illumination in different directions and lighting control. It is the most flexible anti-glare accessory. However, this accessory is relatively large and is generally used with track lights together, neither aesthetic nor convenient. And the light appearance will be affected greatly after adding shading leaves, as well as has a significant impact on the entire interior space.
Soft light glass anti-glare
The soft light glass anti-glare is a special glass material with soft light transmission and anti-glare effect. It’s with a special surface treatment, which can effectively reduce light reflection and dazzle, making it more comfortable for our eyes to watch and avoid causing discomfort or strain. Soft light glass anti-glare materials include frosted glass, textured glass, textured + frosted glass, etc. By reducing the brightness of the surface of the light source, it can achieve a certain degree of anti-glare effect.
Deep inside Anti-glare
Deep inside anti-glare means the light source is placed deeper inside the reflector to narrow the range of the light source, cover part of the light source, ensure that people cannot directly see the light source within a certain visual range, and reduce direct glare. Basically, deep inside anti-glare is to increase the mounting height of the light source (LED chips). It is a common anti-glare method in the market, but the height of the LED lamp body is usually higher, making it not suitable for places with limited ceiling height. Deep-inside anti-glare lighting is widely seen in the LED spot light and LED down light series.
Black light technology
Black light technology is realized through a special shape emitter, and the shading angle of the lamp is exactly the same as that of the light source. In other words, it not only narrows or hides the range of the light source but also avoids the glare produced by the reflector. The LED spotlight is designed with black light technology, which can not only ensure that the light can be emitted normally on the designated path but also ensure that people outside the shading area will not see stray light. From this point of view, black light technology anti-glare lamps are not the same as the commonly known lamp’s surface with black-colored reflectors. Note: Workers need to wear clean gloves during installation to avoid leaving fingerprints, sweat stains, or oil stains on the surface of the reflector.
What are the features of Anti-Glare lighting fixtures?
Glare-Free function: Anti-glare lighting is designed to reduce glare, which is caused by light reflecting off surfaces and into your eyes. It can reduce or avoid discomfort, eye strain, and headaches. People who spend their entire day sitting in front of computer screens or watching television at night before going to bed can benefit greatly from this.
Improved Visibility: UGR19 lighting improves visibility by reducing glare and increasing contrast. This makes it easier to see objects and read text, which can be especially important in work environments where employees spend long hours in front of computer screens or performing detailed tasks.
More Even Lighting: Anti-glare lighting typically uses diffusers or lenses to soften the light and reduce its light intensity, providing even lighting across a room or workspace, reducing shadows, and promoting a productive work environment.
Better Energy Efficiency: Using LED technology can reduce the amount of energy needed to light a space, as it allows for the use of lower-wattage bulbs without sacrificing lighting quality. Compared to traditional incandescent bulbs, LEDs use up to 80% less energy to produce the same amount of light. This means that a 10-watt LED bulb can provide the same brightness as a 60-watt incandescent bulb, resulting in significant energy savings.
Adjustable Angle: Many anti-glare lighting fixtures are adjustable, allowing you to direct the light where you need it most. This can be especially helpful for reading or working on specific tasks.
Increased safety: Anti-glare luminaires increase safety by reducing the risk of accidents caused by glare, such as in outdoor areas with high traffic or in workplaces where precision is required. For example, in outdoor areas such as parking lots, walkways, and roadways, anti-glare luminaires can help drivers and pedestrians see more clearly, reducing the risk of collisions and falls. In workplaces such as factories, laboratories, and hospitals, anti-glare luminaires can improve safety by providing clear and consistent lighting that allows workers to perform their tasks with greater accuracy and precision.
Reduced light pollution: Anti-glare lighting can help reduce light pollution, which can have negative effects on wildlife and the environment.
In addition to increasing the brightness of light sources, suppressing discomfort glare has become an important aspect of lighting engineering in order to create a comfortable visual environment. On the other hand, it is also necessary to ensure appropriate brightness according to the different purposes of the room, so both aspects should be considered comprehensively. In other words, energy-saving LED lamps that feature anti-glare functions and high luminous efficiency will be our first choice.
Luminouslite is a professional architectural lighting solution provider and manufacturer. We produce anti-glare lighting series including anti-glare spotlights, anti-glare downlights, anti-glare panel lights, glare-free linear lights, and outdoor lighting with anti-glare features. All these lighting is with UGR<19 or even less. Whether you’re the owner, designer, architect, or contractor, if you’re unsure how to select suitable light fixtures for your project, feel free to drop us a message. We can supply the best light fixtures based on your lighting design or we can propose a turnkey hospitality light solution according to your lighting project plan.