A few years ago, concerns about migraines and blue light was riding a wave of research into everything from computer screens to the sun at the beach. But does blue light actually make migraine pain worse? Is it dangerous? Are some types of light better than others? And where does green fit in?

New Scientist explains how the results of a study in 2010 were later questioned:

Six years ago, Burstein and his colleagues studied migraine in sufferers who are blind, either due to the loss of an eye or retina, or because of retinal damage. They found that people who had some remaining retinal cells had worse migraines when they were in brightly lit environments, and that blue light seemed to have the strongest impact.

The finding caused a flurry of excitement, and the promotion of sunglasses that filter out blue light. But since then, a special class of cells has been discovered in the retina that process only blue light – and seem to be saved from some types of retina damage that can cause blindness. So there was nothing special about blue light in Burstein’s study – it was just that it was the only type of light his volunteers’ eyes could process.

New Scientist 19 May 2016

Blue light can actually be good – or bad – for migraine patients. As a high-energy visible wave, blue light actually helps with alertness, and can elevate your mood. It helps keep your body keep in rhythm with its environment. All these things are very important for migraine patients.

But as you may have heard, too much blue light at the wrong times can really mess you up – put your rhythm out of whack and even damage your eyes. Hence the concern about “screens”, computer screens and smart phones, especially after dark. This has led to the popularity of blue blocking covers and computer glasses. Many operating systems now have built in options to allow you to “warm” screen colours at sunset (for example, Windows 10 now has “Night Light“, iOS has “Night Shift” … I still like the free f.lux. And don’t forget glasses such as Theraspecs).

But the benefits of these software answers are still in doubt – maybe it’s just better to cut down the screen time!

Cutting out blue light to treat migraine took another hit, a new migraine and colour study was done (with some of the same researchers involved from the 2010 study).

In the new study, published in 2016, blue was not the stand-out light at all. Of four colours (blue, red, amber, and green), blue and red both tended to make migraine pain worse to a similar degree, with amber close behind.

Remember, generally speaking, migraine patients avoid light – the colour may make a difference, but they would simply prefer darkness.

So the surprise is not that these colours bothered the migraine patients. The surprise was that green actually decreased the migraine pain.

Yes, a certain type of green seemed to decrease the pain almost as much as the other colours increased it!

So should we all just wear green glasses?

Not so fast. The green light actually did increase some migraine symptoms similar to the way white light does (throbbing and muscle tenderness). And although green was better than most, migraine pain “spreading” was still reported with the green light.

As with many studies, it’s important that this is another step in our knowledge of migraine, not that it gives us an instant answer, so that we can go out and buy a new product that will solve all our problems.

That being said, if you must have a little light in the room during a migraine attack, try green and see if it’s better.

Also, other studies have indicated the benefits of certain tints for sunglasses and contact lenses.

To read the 2016 study, check out Migraine photophobia originating in cone-driven retinal pathways. Don’t miss the New Scientist article for more on migraines and blue light and green light. You might also enjoy Blue Light: It’s Both Bad And Good For You by Dr. Gary Heiting. For a brief article on the study, see WebMD – Giving the ‘Green Light’ to Migraine Relief.