Along with the spectral distribution of the illumination and its intensity, light flicker is one of the factors influencing visual comfort when illuminating the workplace. Lighting ripple is a rapid, periodic change in light intensity. Under typical conditions, most people are unable to see light ripple above 80 Hz, which is considered the limiting frequency for LED lighting.
Long-term light rippling is a cause of visual discomfort at work. It can cause headaches, migraines and trigger epileptic seizures. In industrial environments, it can lead to accidents involving people, because the stroboscopic effect caused by the light ripple leads to a distorted perception of the speed of rotating objects, such as machine parts. The ripple is highly undesirable in sports venues, concerts, where high quality film cameras are used, often with fast-frame capability (60 frames/s or more), when the effect of changing light intensity becomes apparent. Peripheral vision is more sensitive to the ripple effect, which, in a vehicle driver's situation, can disrupt the driver's concentration and divert attention to the light source, thus posing a risk to road safety.
The rapid development of LED-based lighting technology has made this issue increasingly relevant due to the very fast response time of this type of light source of several tens of ns.