Lysflimmer

Lysflimmer is the perceptual phenomenon of rapid fluctuations in light intensity from artificial light sources. It can be visible to the naked eye or perceived as changes in brightness or color, depending on the modulation frequency, observer sensitivity, and lighting technology. The term is used to describe flicker effects in both household and industrial lighting systems.

Causes of lysflimmer include fluctuations in electrical power supply and the way a lamp or lamp driver modulates light. Common sources are alternating current mains at 50 or 60 Hz, ballast-driven fluorescent lamps, and LED lighting with drivers that use pulse-width modulation or other dimming schemes. Aging components, power quality issues, and improper dimming can also introduce or amplify flicker, particularly at low frequencies.

Perception and health implications vary. Low-frequency flicker, typically below about 60–100 Hz, is more likely to be noticed and can cause discomfort, headaches, or eye strain in some individuals. Some people with photosensitive sensitivity may experience adverse responses to certain flicker patterns. Modern lighting designs often aim to minimize perceptible lysflimmer to improve comfort and reduce potential health effects.

Measurement and mitigation involve assessing flicker using metrics such as flicker percentage or modulation depth, often with photometric instruments. Standards and guidelines from organizations such as IEEE and IEC address flicker in lighting products and electrical installations. Mitigation strategies include employing high-frequency, flicker-free LED drivers, constant-current supplies, improved power quality, and dimming methods that avoid low-frequency modulation.

See also: light flicker, stroboscopic effect, photosensitive epilepsy.