Despite that the energy-saving effect of LED road lighting applications has been recognized and accepted by the market, there are also some criticism and bad comments, including over-bright light sources, serious glare, low product quality, etc.. The State General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) has recent released a related research report: the quality pass rate of existing road lights in our country is only 58.3%, even lower for LED road lighting applications.
Take glare for instance, it will cause eye fatigue and discomfort. Long-term exposed to intense glare even cause damages to our brain. According to the researchers of Philips, glare is the hostile part of the brightness distribution on our visual field, or extreme brightness contrast in space, which causes visual discomfort and reduces the visibility. Imaging a bright spot in the dark field, which makes our eyes difficult to adapt and focus and cause glare, eye fatigue and discomfort.
With the development of LED street lighting industry, more and more manufacturers for LED road lighting applications started to realize the importance of standards, reasonable lighting distribution, visual comfort and user experience. How to overcome these shortcomings became a particularly urgent issue.
Philips carried out a series of studies and researches about glare problems among high-powered LED lighting products, trying to find out reasonable solutions to solve this problem. Color temperature significantly impacts the people’s perception on the glare. Two beams of light with the same output luminous flux, the light with lower color temperature (warm white) will cause less discomfort to our eyes compared with the light with higher color temperature (cool white). One possible reason is that people have preferences on color temperature and brightness. In dim conditions, people prefer warm white color (like dawn, right and dusk), while in bight conditions, people prefer cool white (like daytime).
Researchers from Philips also discovered that the light intensity of light that captured by eyeballs is another important factor leading to glare. For most LED road lighting applications, 80%-90% light could be evenly distributed on the road. But there are still 10%-20% light inevitably dispersed on the edge of the road. A seemingly reasonable approach is to limit the beam on the road, which is also believed as an effective method to reduce glare. However, this edge light is far more useful than it seems like. This part of LED Panel Light could improve the comfort of drivers’ eyes, enabling them to rapid response.