Many of my friends often complain to me that they are sometimes exposed to LED track lights in discount stores, which makes them have to leave the store immediately.
This situation is called glare, which not only affects our visual comfort but also affects our mood. Below, we will share in detail how to control the glare problem of LED track lighting fixtures.
What is glare?
Glare refers to an uncomfortable and reduced visibility visual condition caused by a distribution or range of brightness that is not appropriate within the human field of vision, or by extreme brightness contrasts that exist in space or time.
Or, when light shines on certain objects, the result of light reflection, refraction, and scattering causes the human eye to see intense light. This phenomenon often occurs when looking at mirrors or other smooth surfaces, such as the sun, ice, water surfaces, glass, etc.
What are the hazards of glare?
Glare can also be harmful to human vision and health, which is demonstrated in the following two aspects:
Eye fatigue: Long-term reading or work under strong indoor lighting glare can cause eye fatigue and cause dry eyes, tears, etc.
Visual discomfort: Glare causes visual discomfort, easily distracting people’s attention, and reducing work efficiency.
What is UGR?
The Unified Glare Rating (UGR) is a psychological parameter that measures the subjective response of the human eye to the light emitted by lighting devices in indoor visual environments. It was proposed by Solans in 1987 and adopted by the International Commission on Illumination (CIE).
In simple terms, UGR predicts the amount of discomforting glare caused by lighting devices under a fixed set of conditions. Glare can cause discomfort, headache, or eye fatigue.
Discomfort glare is different from disability glare, which affects the viewer’s ability to accurately identify objects. UGR is a measure of discomfort glare, not disability glare.
Unified Glare Rating Classification
The Unified Glare Rating (UGR) is divided into 7 levels, with the following detailed classification:
| UGR | Subjective feeling | Applicable environment |
| 28 | Severe glare, unbearable | Unsuitable level, not suitable for any environment, indicating high glare level, poor visual experience, harmful to the eyes. |
| 25 | Glare, discomfort | Acceptable level suitable for some special industrial environments such as warehouses and machine rooms, indicating a high glare level and average visual experience |
| 22 | Glare, just uncomfortable Standard level | suitable for general public environments such as malls, passages, elevator lobbies, etc. |
| 19 | Slight glare, tolerable Comfortable level | suitable for home, office, classroom environments, etc. |
| 16 | Slight glare, ignorable | Rest, sanitary and emergency rooms, offices, etc. |
| 13 | Extremely slight glare, no discomfort | Rooms requiring delicate operations |
| 10 | No glare | Rooms requiring long-term delicate operations |
What UGR index is required for various commercial spaces?
The requirements for the UGR index of various commercial spaces vary according to their functions and purposes. The following are some suggested UGR index requirements for commonly used spaces, but actual conditions may need to be adjusted based on specific design and local laws and regulations:
| Space name | UGR |
| Office | <16 – <19 |
| Conference room | <16 – <19 |
| Restaurant or dining area | <19 – <22 |
| Retail store or shop | <19 – <25 |
| Stadium or gym | <19 – <22 |
| Classroom or training room | <16 – <19 |
Causes of light glare
Direct Glare
Direct glare is glare caused by light sources or high-brightness objects directly entering the eyes. When the light source or high-brightness object is in the line of sight and its brightness is significantly higher than the surrounding environment, it will cause direct glare. This glare can cause discomfort and visual fatigue, affecting people’s productivity and safety. Common sources of direct glare include sunlight, bright lamps, television screens, and computer monitors, among others.
To reduce direct glare, the following measures can be taken:
1.Choose lamps with good light distribution performance or control the brightness of lamps to evenly emit light, making the brightness contrast in the space appropriate.
2.Adjust the installation position and light-emitting angle of the lamps to avoid direct light entering the eyes.
Reflective Glare
Reflective glare refers to the glare caused by light entering the eyes after reflecting off an object. When light is shone on a smooth or glossy surface, a high-brightness reflection area is formed. This reflected light can cause discomfort, especially during long-term work or reading.
To reduce reflective glare, the following methods can be used:
1.Choose low-reflectance or matte surface materials, such as furniture, flooring, and walls, to reduce the reflection rate of the light source.
2.Adjust the installation position and light-emitting angle of the lamps to reduce the possibility of light directly shining on easily reflective objects.
3.Use indirect lighting techniques to shine light on the ceiling or walls and then provide ambient lighting through reflection.
Indirect Glare
Indirect glare refers to the glare effect caused by the reflection and scattering of light on multiple surfaces. Although indirect glare is relatively weak, it can cause light pollution and blurriness in the visual environment, affecting visual comfort and clarity. Indirect glare can originate from multiple reflective surfaces such as walls, furniture, floors, and ceilings. Due to multiple reflections, brightness and contrast may decrease, but it can still cause visual discomfort.
To reduce indirect glare, the following measures can be taken:
1.Choose appropriate interior decoration and furniture materials to reduce multiple reflections on surfaces.
2.Optimize lighting fixture layout to minimize the impact of indirect lighting on the line of sight.
3.Use multiple lighting strategies such as combining ambient lighting, task lighting, and local lighting to achieve a comfortable and efficient visual environment.
4.Control lighting brightness and color temperature to maintain visual comfort and clarity in the space.
The design principles for LED track lighting anti-glare design
LED track lighting is widely used in commercial spaces, galleries, museums, etc., and has both lighting and decoration functions. In order to improve visual comfort and reduce glare, the following anti-glare design principles can be followed:
Reasonable shielding angle
According to the installation height of the lights, the shielding angle of the lights should be reasonably designed so that the light source is partially shielded to ensure that there is no direct light exposure within the line of sight of people during activities. The following are suggestions for the design of track lighting shielding angles:
Generally, the shielding angle of track lighting should be greater than 30 degrees and less than 60 degrees, which can achieve adequate shielding and scattered light.
For places that require strong spotlighting effects, such as exhibitions or galleries, the shielding angle can be appropriately reduced to better focus the light.
For places that require widespread environmental lighting, such as commercial spaces or restaurants, the shielding angle can be appropriately increased to better diffuse the light.
The shielding angle of track lighting can also be adjusted according to the height of the lights and the size of the target lighting area. Higher lights can choose a smaller shielding angle, while lower lights need a larger shielding angle.
The distance between lights is also an important factor in the design of the shielding angle. If the distance between track lights is small, a smaller shielding angle should be selected to avoid glare.
Evenly Distributed Illumination
Choose a lighting fixture with good illumination performance, to evenly distribute the light in the illuminated area, avoiding overly concentrated or uneven brightness distribution. For example, a lighting fixture with a lens or reflector can be selected to control the beam distribution.
Controlling Light Source Brightness
Maintain an appropriate level of brightness to reduce glare. Dimming technology can be used to adjust the brightness according to the scene or time period. Avoid excessively high light source brightness with a large contrast to the surrounding environment.
Reasonable Layout and Angle
Arrange the track lighting layout and illumination angle reasonably, to ensure that the light does not directly shine into the eyes. The direction and height of the lighting fixture can be adjusted according to the spatial structure and use requirements, so that the light shines from the side or top.
Indirect Illumination
Use indirect lighting technology, such as illuminating the ceiling or wall and providing ambient lighting through reflection, to reduce glare and create a soft light environment.
Avoiding Reflective Glare
Pay attention to the reflection of light on smooth or glossy objects, such as floors, furniture, and exhibits. The lighting angle and layout can be adjusted, or low-reflective surface materials can be selected to reduce reflective glare.
Color Temperature and Color Restoration
Choose a light source with an appropriate color temperature and high color rendering index (CRI), to provide a natural and comfortable light environment. Avoid using overly cool or warm color temperatures and low color rendering index light sources, which may cause visual discomfort.
What are the accessories for controlling glare from lighting fixtures?
Shade
The shade of a lighting fixture is a device that covers the fixture and is designed to reduce light scattering and control the direction of light emission. The shade is usually fixed on the fixture and sometimes it is also movable.
The first function of the shade is to prevent light scattering and reduce the shading angle of the fixture, thus reducing glare. The second function is to control the direction of light from the fixture, which enhances lighting performance and efficiency, and reduces light pollution.
Reflector
The reflector of a lighting fixture is an optical element that reflects and redistributes light to improve lighting efficiency and enhance the direction of light. The reflector is usually made of mirror or reflective material and is fixed inside or outside the fixture.
The reflector can redistribute light to a larger area and control the direction of light from the fixture, which helps control glare and enhances lighting performance and efficiency.
Honeycomb grid
The honeycomb grid is a mesh structure accessory, usually made of metal or plastic, installed outside the fixture to control the direction and scattering of light.
The main functions of the honeycomb grid are:
Control light direction: The honeycomb grid can focus light in a specific direction, improving lighting performance and efficiency.
Reduce glare: The honeycomb grid can prevent light scattering and reduce glare.
Improve indoor decoration: The appearance of the honeycomb grid can also improve indoor decoration and coordinate with the appearance and design of the fixture.
Soft Panel
The soft panel of a lighting fixture is an optical accessory that softens and diffuses the strong light from the light source, making the light more uniform and soft, reducing the directness and strong contrast of the light, and producing a more natural and comfortable light and shadow effect on the illuminated object.
The soft panel can be made of soft materials such as cloth, paper, or plastic, or it can be made of hard materials such as glass or acrylic. They usually achieve the effect of soft light through different scattering principles and material characteristics. These panels can be installed in the front of the fixture or used separately between the light source and the fixture.
In home and office lighting, soft panels can also provide a more comfortable light environment, reduce glare, and reduce eye fatigue.
How to avoid glare from LED track lighting in the office?
Glare control is very important for the office environment, as the office is a place where we work and live. If there is glare interference during work, it will not only affect work efficiency but also cause eye fatigue and headaches. Therefore, glare control is very important in the office environment, which is not only good for human health but also beneficial for improving work efficiency.
Next, we will analyze how to avoid glare from LED track lighting in the office from two aspects: lighting fixture selection and lighting fixture layout.
Lighting fixture selection
In the office, we usually need light to be evenly illuminated on the desktop and the light to be soft, as soft light has a weaker reflection ability, which will be helpful in reducing reflection glare.
We can choose track-style panel lighting fixtures with frosted panels, or directional crystal materials can be used on the panels to control the direction of the light. Deep-embedded point-emitting track-style panel lights are also a good choice, as these lighting fixtures have well-designed shading angles and can effectively avoid glare.
Choosing semi-indirect or indirect LED track lighting is also a good option, as the light is reflected from the ceiling, making the entire ceiling’s brightness contrast within an appropriate range, which is very beneficial in reducing glare. However, this type of lighting fixture requires the choice of a suspended ceiling, and it is not suitable for industrial-style exposed ceilings.
Lighting fixture layout
Install the lighting fixtures directly above the desktop, parallel to the direction of the desktop, and consider the reflection problem of the computer monitor to avoid direct and reflected glare.
How to Avoid Glare with LED Track Lighting in Supermarkets?
Glare control is also very important in supermarkets. Supermarkets are where we shop, and if there is glare interference during the shopping process, it will not only affect our correct viewing of the products but also affect the overall shopping experience. Therefore, glare control is very important in supermarkets, which not only helps to create a comfortable shopping environment for customers but also increases their stay time and improves the supermarket’s sales rate.
Fixture Selection
In the supermarket environment, we typically use LED track spotlights in the product display area to highlight products on the shelves. First, we need to determine the power of the fixture. For places where the fixture installation height is low, we need to choose low-power LED track spotlights, and for places with a higher installation height, we need to choose high-power LED track spotlights, and the height of the level also affects the selection of the light beam angle for our fixtures. Typically, in places with lower installation heights, we usually choose fixtures with slightly larger beam angles, such as around 55 degrees, which will affect our choice of the fixture’s shading angle.
As mentioned above, the shading angle selection of track spotlights is between 30 and 60 degrees, which is beneficial for controlling scattered light and achieving glare control requirements. We can also choose track lighting fixtures with shading accessories, which can easily adjust the shading angle of the fixture and achieve good glare control effects for various installation environments.
Fixture Layout
In supermarkets, we need to avoid the direction of people’s activities. The light from LED track spotlights appears directly within the range of human eyesight. For example, the fixtures should be aimed at the two sides of the activity range and should not be installed to shine directly into people’s eyes. The angle of the lighting fixtures should also be controlled. For example, in the case of lower shelves, if the light from the LED track spotlights scatters, it may affect customers in other areas and cause glare.
There are many reflective furniture and components in supermarkets, such as glass and floor tiles. When arranging lighting fixtures, we also need to consider the glare caused by the reflections of these objects.
Some supermarkets may also use track spotlights for cashier lighting. When installing fixtures, we need to pay attention to the angle of the lighting fixtures, which should not cause glare to customers and cashiers, and select fixtures with suitable shading angles.
How to avoid glare in restaurants with LED track lighting?
Glare control is equally important for restaurant lighting. We enjoy delicious food and socialize in restaurants. If there is glare interference during the dining process, it will affect the dining experience for customers and make them reluctant to stay longer in the restaurant. This can lead to customer loss and impact the restaurant’s brand image.
A restaurant with good glare control not only provides a pleasant dining environment for customers but also increases their retention rate, which is crucial for the restaurant’s success.
Light fixture selection
Restaurants usually need to use LED track light fixtures for key lighting and ambient lighting. For highlighting decorative items or special corners, choose light fixtures with smaller beam angles. For background wall or atmosphere creation with wall washing lighting, use special wall-washing light fixtures with polarized light characteristics.
Light fixture layout
When arranging LED track light fixtures in a restaurant, arrange the fixtures based on the objects to be illuminated, and avoid directing the light head towards the walkway or dining areas. When lighting decorative objects or walls, pay attention to the reflection of the illuminated objects, adjust the installation position and angle of the light fixtures, and install accessories such as shading covers or honeycomb mesh covers for glare control.
What is a UGR<19 light fixture?
The UGR index is usually evaluated for a space, but many manufacturers describe their light fixtures as “UGR<19” in their sales materials. So, what does this mean?
Generally, fixtures marked “UGR<19” have good shading angle control, making most of the light from the fixture shine downwards without scattering. Some fixtures project light upwards for indirect illumination.
This means that using these fixtures at typical heights and spacing in the intended environment can help lighting designers better achieve a UGR<19 in that space. However, this does not guarantee that using these fixtures in offices or classrooms will result in a UGR＜19 situation. The layout and installation height of the fixtures must also be considered to meet UGR requirements.
FAQ
How much UGR is required for offices?
According to standards, the UGR for ordinary offices should be controlled below 19, and offices requiring fine work should have a UGR controlled below 16 to ensure a comfortable visual environment.
What are the ways to control the shading angle of LED spotlights?
Controlling the shading angle of LED spotlights can be achieved by selecting track light fixtures with shading accessories, considering the reflection of spotlights on reflective furniture and components when arranging light fixtures, and controlling the illumination angle of the fixtures.
How to avoid direct glare?
To avoid direct glare, control the shading angle of LED spotlights, select light fixtures with appropriate power and beam angles, and arrange fixtures reasonably to avoid people’s activity direction.
How to avoid indirect glare?
To avoid indirect glare, choose track light fixtures with shading accessories and consider the reflection of fixtures on reflective furniture and components when arranging them.
What is a UGR<19 light fixture?
Fixtures marked “UGR<19” have good shading angle control, making most of the light from the fixture shine downwards without scattering, making it more convenient for offices to achieve the specified UGR value.
