1 Introduction

2 What Is Glare and Why Does It Matter?

2.1 Disability glare

2.2 Discomfort glare

2.3 Glare recovery

2.4 Reflected glare

3 What Factors Affect Glare?

3.1 Light source intensity and illuminance

3.2 Light source luminance

3.3 Background luminance

3.4 Light source location

3.5 Light source spectral distribution

3.6 Glare exposure duration

3.7 Observer age and other characteristics

3.8 Psychological factors in discomfort glare

4 Modeling and Predicting Glare

4.1 Disability glare modeling

4.2 Discomfort glare modeling

4.3 Glare recovery modeling

4.4 Reflected glare modeling

5 Hints for Designing to Control Glare

5.1 Disability glare control

5.2 Discomfort glare control

5.3 Glare recovery control

5.4 Reflected glare control

6 Future Outlook

7 References

Preface

When I tell people I work in lighting, I often get a blank stare in return, or the question "Why?" When I mention that a lot of my research has to do with seeing better while driving at night, those blank stares often turn into impassioned pleas for "doing something about those bright headlights!" Like many things, lighting is something that is noticed mainly when it’s doing something wrong. Glare is an unfortunate part of lighting that has given me an opportunity to "do something" to help make walking and driving at night safer and more comfortable by identifying glare's causes and countermeasures. My investigations of glare have been published across many different journals, conference proceedings and technical reports, so I am grateful to SPIE Press for allowing me to consolidate them into this Spotlight. I hope this eBook can be a genesis for an Integrated Glare Metric (IGM) to help us tame the glare from headlights, streetlights, displays and windows. Many thanks to Mark Rea and Mariana Figueiro at the Mount Sinai Light and Health Research Center (LHRC) for urging me to submit my book proposal to SPIE, and to Mark for feedback on my drafts. I also appreciate the support from the members of the LHRC's Light for Transportation Safety Partnership (ams OSRAM, Audi, General Motors, Hella, Lumileds, Marelli, and Varroc) that made it possible for me to complete this project.

John D. Bullough
August 2022