<p>LEDs are no doubt preferable from an environmental standpoint but when it comes to health risks due to the high flicker rate, little is known. Unfortunately, most popular LED lighting brands in India use technology that causes 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.</p>.<p>If your child frequently complains of eye strain, fatigue, headache and sometimes a migraine while studying, it’s 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 vision or you notice he’s more distracted and often irritable during study time, you need to solve flickering issues immediately.</p>.<p>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<br />light above 60-90Hz. The effects of flicker include eye strain, fatigue, headache, migraine, blurred vision and photo epilepsy in sensitive individuals.</p>.<p>A flicker may not be always harmful 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.</p>.<p>One of the simple and effective methods for you to detect light flicker in LEDs is through your mobile phone camera in slow motion mode.</p>.<p>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.</p>.<p><em><span class="italic">(The author is ophthalmology consultant, Fortis Hospital)</span></em></p>
<p>LEDs are no doubt preferable from an environmental standpoint but when it comes to health risks due to the high flicker rate, little is known. Unfortunately, most popular LED lighting brands in India use technology that causes 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.</p>.<p>If your child frequently complains of eye strain, fatigue, headache and sometimes a migraine while studying, it’s 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 vision or you notice he’s more distracted and often irritable during study time, you need to solve flickering issues immediately.</p>.<p>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<br />light above 60-90Hz. The effects of flicker include eye strain, fatigue, headache, migraine, blurred vision and photo epilepsy in sensitive individuals.</p>.<p>A flicker may not be always harmful 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.</p>.<p>One of the simple and effective methods for you to detect light flicker in LEDs is through your mobile phone camera in slow motion mode.</p>.<p>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.</p>.<p><em><span class="italic">(The author is ophthalmology consultant, Fortis Hospital)</span></em></p>