You know that LEDs are preferable from an environmental standpoint. Not much is mentioned with respect to the human and consumer side of things,especially when it comes to the health risk of their high flicker rate.Unfortunately, most popular LED Lighting brands in India use technology that cause flicker at frequencies that may have adverse health effects. The effects of flicker include eye strain, fatigue, headache, migraine, blurred vision and photo epilepsy in sensitive individuals
If your child frequently complains of eye strain, fatigue, headache and sometimes migraine while studying, it’s the time to check your LED lighting, which could be the possible reason for such symptoms. Even if you find that his reading performance has degraded over a period of time along with a general deterioration in visionor you notice he’s more distracted and often irritable during study time, you need to solve flickering issues immediately.
Flicker is nothing but a rapid and repeated change in the brightness of light over time. While visible flicker is consciously perceived and is considered unpleasant with biological and/or health effects on humans, invisible flicker is not consciously perceived, nevertheless it may still have biological and/or health effects on humans. Most humans are unable to perceive flicker in light above 60-90Hz.The effects of flicker include eye strain, fatigue, headache, migraine, blurred vision and photo epilepsy in sensitive individuals.
According to IEEE 1789 titled, IEEE Recommended Practices for Modulating Current in High-Brightness LEDs for Mitigating Health Risks to Viewers, “The healthiest lighting solution is quite clearly one which does not flicker, like the light which nature provides in the form of daylight. We should remember that even a frequency of 100-400 Hz, at which many LED luminaires operate nowadays, has negative effects on the human organism. Even flicker is not directly visually perceptible in these ranges.
Importantly, flicker may not be always harmful to you but in certain environments such as classrooms, offices, hospitals, industrial spaces and even homes where children/adults are exposed to light during several hours every day it can cause considerable health issues. “Moreover, children are more vulnerable to flicker induced effects than adults. Flicker in certain industrial settings can cause performance issues, and even accidents.
Factors that make flicker worse are longer duration of exposure, greater area of retina receiving stimulation, central location in the visual filed as it projects to a greater area of the visual cortex, greater brightness of the flash, and higher contrast of the flash with the surrounding luminance.
It is because of these reasons California State in United States of America has defined the standards. Unfortunately, there are no standards in India and most LEDs have flicker rate of anything between 40% to 80% much higher than the California benchmarks. The root problem is that in our country there’s no single regulatory pathway for LEDs that flicker and they slip through the cracks.
The problem needs to be addressed in a county like India, where regulation can be lax. At individual level, adopting a proactive stance is the only key to protect your wellbeing. One of the simple and effective methods for you to detect light flicker in LEDs is through your mobile phone camera in the slow motion mode. By simply targeting the LED lamp and looking it in the mobile screen in the slow motion mode, you can easily determine the flicker in LEDs. Also, as a buyer, once you learn to recognize flicker rates of different LED products, you can easily avoid purchasing LEDs with questionable flicker rate and this will significantly reduce the risk of several health issues associated with it.
BY: Dr. Mayank Bansal, Ophthalmology, Consultant, Fortis Hospital