Light is a common migraine trigger and can intensify the pain experienced during a migraine attack with only seconds of exposure. Retreating to a dark room during a migraine often brings relief of symptoms within 20-30 minutes. About 40% of those who experience migraine have significant issues with light triggering migraine attacks.
There are different aspects surrounding light that can affect those who experience migraine and some may act as triggers whilst others only become a problem once a migraine attack has started. Eye strain caused by inadequate lighting or screen overuse is also a migraine trigger and it can be difficult to find the right balance between reducing light when it is the culprit without reducing it to the point where lack of light is the cause.
It is difficult to accurately identify triggers, particularly as triggers also interact and as a general rule, multiple triggers can lower the threshold of a trigger so that something that would not ordinarily cause a migraine, do so because of other contributing factors, but light is not only a migraine trigger. Light sensitivity is a cardinal feature of migraine and one the diagnostic criteria for the disorder and avoiding the detrimental effects of light can reduce both the intensity and duration of migraine symptoms.
Bright light and glare
Glare caused by bright light is a well known migraine trigger and exacerbate an existing migraine episode. According to the Lighting Research Centre, “Glare is a visual sensation caused by excessive and uncontrolled brightness. It can be disabling or simply uncomfortable. It is subjective, and sensitivity to glare can vary widely.”
Reducing exposure to glare is not too difficult to do at home. Position furniture so that sunlight does not hit your eyes early or late in the day and invest in blinds and curtains that block out light to various degrees. Sometimes a set of thin curtains that filter light by a small amount can make the difference, whilst during a severe attack is it important to have the option to block out light completely, particularly in the bedroom.
Artificial light can also cause glare. Use low intensity bulbs or lamps with thick shades. Turn on lamps instead of overhead lights and create diffuse light. Don’t overdo light reduction. It is possible to create a well-lit room without glare and light that is uncomfortably bright.
To avoid screen glare, use an e-reader instead of a back-lit device when reading, turn down screen brightness and take frequent breaks.
Bright light and glare is more difficult to control when going out. Avoid travelling at dusk and dawn. On bright summer days, wear sunglasses and choose attractions where natural light are naturally reduced, such as visiting woods and places with lots of trees and shading. Check in advance if a venue makes extensive use of older fluorescent lighting and when staying in a hotel, take your own bedside lamp in case the lights are too bright.
Flicker happens when light shines unsteadily or a light source changes from bright to dim quickly and repeatedly. Flicker used to be a big issue in the age of CRT monitors and old fluorescent lights, but modern screens and bulbs do not flicker with a steady current and so it has become less of an issue. Early compact fluorescent bulbs flickered, but modern high-quality bulbs refresh at a rate higher than 60Hz, which means that they are flicker free as the human eye and brain only detect light as flickering under 50Hz.
Invest in good quality new bulbs and test if they flicker before using them. LED’s will not flicker if given a steady DC current, but when AC current (mains) is converted to DC, a capacitor is normally used to smooth the output – if the capacitor isn’t working or the transition isn’t done well, LED lights flicker. Older compact fluorescent bulbs flicker and as they can last years, if you don’t know how old yours are, replace them to see if that fixes the problem.
Screens no longer flicker unless faulty, but some visual images in video games, movies, tv series and other entertainment may be of flickering light, so look out for that when choosing what to watch or play.
Avoid using candles that flicker, particularly during an attack. Some public spaces make use of flickering light to create atmosphere, like clubs or fair grounds. If light is an issue, visit fair grounds in the day time when lights are less effective and often not even turned on and avoid indoor venues known to use atmospheric flicker and flash lighting.
Some bright patterns, particularly chequered, striped and zig-zag patterns, can trigger or worsen a migraine for some who experience light sensitivity as a symptom. Avoid black and white or bright coloured patterns in flooring, furniture and clothing. If this is a significant problem, check the decor of hotels in advance before reserving a room or ask for a room with neutral colours.
Blue spectrum light
Blue spectrum light, including ‘cool white’, can be problematic for those sensitive to light. LEDs naturally omit more blue light and so do some compact fluorescent bulbs.
Check the Kelvin rating before purchasing – low Kelvin bulbs emit warmer light in orange/yellows whilst higher Kelvin ratings mean cooler blue to white light.
Use a filter on electronic devices. Filters can reduce blue spectrum light emitted by electronic screens as well as lights. Some light bulbs have a filter as part of the casing that can reduce the amount of blue light. Look for these. Pick up an application for screens that change the colour temperature, like f.lux that adjusts both the warmth and intensity of light emitted by the screen.
Use natural light when possible and find light-free alternatives, for example choose an ereader instead of a backlit screen. Also choose friendlier light alternatives – e-readers for example, have a light that shine from the top onto the text instead of light shining from behind the text which makes them a better choice.
Try some glasses. There are speciality tinted glasses on the market, like Theraspecs and MigraLens, which block out particular types of light.
Make sure it is blue light that is actually the problem. It can be difficult to determine the exact trigger as triggers differ from person to person. Eliminate flicker, glare, dazzle and badly positioned lighting first before resorting to try and eliminate all LEDs and screens.
Light has a complex interaction with migraine symptoms in those who are sensitive to light. For some it acts as a trigger, for others it only becomes an issue during an attack and the unlucky experience both. For some is the brightness and glare that is the problem, for others it is flickering light or bright patterns, whilst some are particularly sensitive to blue spectrum (and grey and red to a lesser extent) light and again, it is all of the above for some.
It is a difficult task to try and figure out which aspect of light might be a trigger or contributing factor, but as it is a significant problem not only during an attack, but also as a trigger that can cause one, it is worth investing the time to discover and then reduce the negative aspects around light that trigger or worsen migraine for you. Don’t jump to conclusions. Light isn’t a bad thing, artificial light isn’t evil and avoiding light regularly can cause increased light sensitivity as chronic dark adaptation occurs and all light seem brighter all the time, making exposure to light even more debilitating. Not enough light can also trigger a migraine.
Be sensible and find a balanced approach to change the role light plays in your environment instead of aiming to eliminate it.