If you’re having a migraine, your head will typically throb from one side (this can even be the forehead and eye area). You may feel nauseous, vomit and become increasingly sensitive to smells, sound, light (especially bright light such as LEDs or screens). Bright lights and screens all emit light in the full spectrum of wavelengths, but are concentrated in the range of 380nm-550nm which includes blue light. This brings into question the relation between blue light and migraines.
In contrast, if you have a headache, you’ll feel a pressing or tightening situation, usually on both sides of your head. The most common type of headache is a tension headache caused by stress, muscle strain and anxiety. Physical activity won’t worsen the pain (as with migraines) and you won’t be as sensitive to blue light.
Migraines aren’t fully understood but environmental factors come into play in triggering or worsening migraines. Changes in the chemicals in the brain- including serotonin have been discovered to be involved. The following are common migraine triggers;
The majority of migraine sufferers are women and changing levels of estrogen before and after pregnancy, periods and menopause have been linked with migraines.
Light and other visual stimuli can cause migraine attacks.
During a migraine, photophobia (increased sensitivity to light) is common. 80%-90% of those with migraines experience photophobia and become sensitive to even low levels of light.
Light, especially bright lights which contain blue light can cause migraine attacks to start. Additionally, flickering or pulsing light, glare and repetitive patterns and blue light can cause a migraine to start. Fluorescent light (such as LEDs) contains invisible pulsing, so many report that it triggers migraines.
Missing out on sleep, sleeping late at night, poor sleep quality, irregular sleep patterns and jet lag have been linked with migraines. Blue light exposure late at night has also been linked to disturbances in sleep patterns and insomnia.
Stress causes changes in serotonin levels in the brain, which is why it can trigger migraines.
Many other factors such as weather changes, medications (oral contraceptives and vasodilators), alcohol, caffeine and food additives such as MSG may trigger migraines for some. It is thought that the above triggers result in the blood vessels to the brain becoming constricted. As a result blood flow to the brain is resulting in a migraine.
Several scientific findings show the relation between blue light and migraine attacks and headaches in people who are susceptible to them.
There is a distinct neural pathway from the eyes to the brain—unrelated to how vision is transmitted—that causes blue light wavelengths to aggravate headache pain and other symptoms.
The wavelength of blue light is in the range of 480nm-550nm. Exposure to this blue light induces extreme irritation, heightened pain sensitivity and throbbing, and even increased headache pain scattered across the brain.
Scientists became interested in whether blue light can cause migraines when they found out that even blind people suffer from photophobia and light-induced migraine attacks. Since blind people don’t have normally functioning rod and cone cells in their eyes, why does light affect them?
Quick refresher: Cone cells detect colours and help us see during the day, while rod cells aid in night vision. They are both present in the retina of the eye.
If these cells aren’t active in the people who can’t see, how is there still a functional connection between their eyes and their brain?
In 2002, researchers discovered a third kind of eye cell, in mice. Intrinsically photosensitive retinal ganglion cells (ipRGCs) have nothing to do with vision. Instead, they sense blue light and relate changes in blue light in the surroundings, to the brain.
IpRGCs create their own light-sensitive protein called melanopsin, which is more sensitive to blue light than retinal rods and cones. Rather than controlling vision and enabling us to see colour, ipRGCs organize involuntary functions like circadian rhythms and the pupillary light reflex (PLR). These cells sense blue light in the surroundings and transmit signals to the brain. The brain responds by promoting wakefulness and releasing hormones such as cortisol, which are responsible for alertness.
Since most migraine sufferers are troubled by blue light, ipRGCs are a prime suspect in the development of photophobia and migraines.
By proactively wearing blue light blocking lenses, migraine sufferers can experience reduced attacks, relief from headaches and visual eye strain associated with triggering light, while going about their day-to-day lives without the stress of not having a defense against an impending episode. But not all blue light blocking lenses are the same. Blue light comparisons must be made at 455 nm. Digital devices and LED lights emit blue light from about 430 nm to 500 nm with an intense spike at 455 nm. Majority of blue light “blocking” lenses only provide blocking percentages in the part of the spectrum where digital devices emit little to no blue light, making their protection insignificant. At Eyelation we recommend wearing BlueTech lenses. These lenses offer 45-59% protection, compared to competitors that only offer 3-9% blocking protections.
*Content and Images Sited from BluTech lenses & The Canadian Association of Optometry