If you experience light sensitivity (photophobia) that can trigger migraine attacks, then a little science can go a long way to help you understand and manage light-triggered headaches.
All light sources share one thing in common, they transmit the
following primary colors: red, blue and green, or RGB. As light enters our eye, it is processed by our retina for image recognition. The retina consists of three color sensing receptors called ‘cones’ that are stimulated by either blue, green or red frequencies.
For the scientist in us, and for discussion purposes, the frequency of visible light is measured between 400 to 700nm (nanometers) with each of the three cones responding to the following frequency ranges:
Different light sources can vary with intensity and frequency of RGB. Blue light is ubiquitous in just about every light source and the main color frequency associated with the onset of headaches. Blue light intensity varies from high to low by a light source, as follows:
Compact fluorescent (CFL) and newer LED (light-emitting diode) lights are prominent and provide bright light with low energy consumption… good for our pocketbook and the environment. CFLs transmit blue light with spikes at 405 nm and 430 nm and, when combined with the annoying flickering, can trigger headaches for light sensitive individuals. LEDs use about 65% less energy than CFLs, are much brighter and last longer, making LEDs the most popular option today for indoor lighting, outdoor lighting, digital devices and screens. The downside is that LEDs can also trigger detrimental headaches because they transmit blue light from about 425 to 500 nm with an intense spike around 455nm, which closely overlaps the blue cone’s peak sensitivity point. This might help explain why more people who suffer from migraine attacks want to avoid computer use or brightly lit environments like a big box store, school, hospital, etc. Understanding how light works and having the right protection is essential for anyone wanting to combat its impact.