In the world of lighting, flickering light can be categorized as either visible or invisible, consciously perceived by observers or involuntarily affecting human well-being and health. The occurrence of this effect is influenced by various factors, including power supply systems, current and voltage quality in the network, and the types of luminaire control solutions employed.
Unfortunately, this issue extends to all light sources, encompassing both traditional light bulbs and energy-efficient LED systems. Even a few seconds of exposure to flickering light or prolonged use of a defective light source can have noticeable side effects.

Impact on Health
Prolonged exposure to light with a frequency exceeding 70 Hz in a room can have adverse effects on our well-being and overall health. Installing electromagnetic ballasts in the system can help mitigate the risk of complications. However, it’s important to note that over time, the quality of emitted light deteriorates, leading to a decrease in its frequency. Besides frequency, the flickering effect is influenced by waveform and modulation levels.
The following parameters are used to study the effects of flickering:
- Flicker Percent: This parameter determines the cyclic variation of light amplitude. It can be calculated using the formula: Flicker Percent ≤ 0.0333 * flicker frequency [HZ]. It is based on the fact that flicker frequencies above 3000 Hz meet safety requirements.
- Flicker Index: This factor considers the percentage of flicker, waveform shape, and duty cycle, and should ideally fall within the range of 0 to 0.1.
Strobe Effect
In addition to light flickering, there is another phenomenon known as the strobe effect, which alters visual perception by creating the illusion of stopping or slowing down. This effect poses a potential threat to human health and safety. The SVM parameter can be used to determine the presence of the strobe effect. A value of SVM ≤ 0.4 significantly reduces the likelihood of this phenomenon occurring.
Light Ripple and LED Lighting
Light emitting diodes (LEDs) are highly sensitive to fluctuations in power. Momentary power surges in the electrical network can result in a flickering effect. To mitigate this, protective filters are used in LED power supplies. When purchasing LED bulbs, it is crucial to prioritize quality to minimize the risk of flickering. It’s worth noting that faulty electrical installations can also contribute to this phenomenon, so it is advisable to inspect the installations in case of any LED-related issues.
Lighting plays a significant role in our health and well-being as we encounter numerous sources of artificial light throughout our day, both at work and during leisure activities. Investing in luminaires with high-quality lighting parameters can greatly reduce the risk of flickering or stroboscopic effects, promoting a healthier and more comfortable lighting environment.
For more information on lighting and its effects, please visit authoritative websites such as Lighting Research Center, International Commission on Illumination (CIE), and Energy Star.