深入了解 UGR＜19 的真正含义

If you work with lighting, you have probably seen the specification UGR <19.

But what does it actually mean?

UGR <19 Means Low Potential Glare

UGR stands for Unified Glare Rating and is used to evaluate discomfort glare from lighting.

In simple terms:

Lower UGR means lower potential discomfort glare.

So, UGR <19 indicates a low level of potential discomfort glare under the relevant lighting conditions.

It does not mean that there is no glare. It means that the lighting is designed to provide good glare control.

Why Is UGR <19 Important?

Glare becomes more important when people need to concentrate or perform visual tasks for long periods.

For example:

• Offices — working with computers and documents
• Classrooms — reading, writing, and learning
• Libraries — prolonged reading
• Meeting rooms — screens, presentations, and communication

In these environments, lighting needs to provide not only enough illumination, but also comfortable visual conditions.

Does UGR <19 Always Mean Better Lighting?

Not necessarily.

UGR is only one part of lighting quality.

A good lighting solution also needs to consider illuminance, light distribution, beam angle, color quality, efficiency, and the function of the space.

Different spaces have different requirements. A retail store, restaurant, office, and home do not necessarily need the same level of glare control.

The goal is not simply to achieve the lowest possible UGR.

It is to achieve appropriate glare control for the space and its users.

What Does UGR <19 Mean to People?

For a lighting designer, UGR <19 is a technical specification.

For the user, it means something simpler:

More comfortable light for prolonged visual tasks.

That is the real value behind the number.

At KOE, we believe lighting quality is not only about how much light we produce, but also how comfortably people experience that light.In the next article, we will look at how UGR is calculated and why the same luminaire can produce different UGR results in different lighting environments.