Two female creatives working in front of two Lumie Vitamin L lights receiving bright light therapy

Bright light therapy guide

Bright light therapy is a first-line treatment for Seasonal Affective Disorder (SAD) and Winter Blues and is also considered an effective treatment for non-seasonal depression and bipolar disorder. It can be used to correct your body clock and sleep problems, help you adjust to new timezones or shift patterns and for a general energy boost. It is a safe, efficient and effective treatment for most people, but isn’t suitable for everyone, so you should always consult with your doctor before starting to use a SAD light of any type. If your doctor has given you the go-ahead to try bright light therapy, let’s answer some questions you might have so you can choose the right light for you and get the most out of your therapy.

In this article, we’ll cover a lot of questions, so if there’s something particular you want to know, use the links below to get to that question quickly:

Why use bright light therapy?

Our bodies understand what time of day it is by receiving light cues through our eyes. The light signals to a master clock in the brain that controls the clocks that are found in every other cell in our bodies. This helps the different parts of our body to know when to carry out different activities such as to sleep or wake up, eat, be active or rest. Light is of huge importance to our physical and mental health. It is only in the last 30 years or so that research has begun to focus on this area, and there are lots of exciting discoveries being made.

Before the invention of electric lights, we lived our lives according to day/night cycles and would only have had access to firelight after sunset. We have gone from being hunter-gatherers to agriculture workers, to the industrial age, spending less time outdoors and we now spend 90% of our time indoors. Now, we have the means to manipulate our environments and can make it seem like daylight in the middle of the night. While this might be desirable for our lifestyles, our bodies are still stuck in the stone age and haven’t adapted yet to how we live our lives in the modern age.

When we’re indoors all day under a consistent level of light, it’s difficult for our brain to figure out what time of day it is. General lighting in homes tends to be around 100-300 lux (a measure of light intensity) and in offices around 300-500 lux. Outdoors on a clear spring morning the light level would be around 10,000 lux and on a sunny summer afternoon, it can be 100,000 lux.

Man working next to colleagues at computers, with Lumie Desklamp SAD light, a type of bright light therapy device.
Lumie Desklamp SAD light

The best thing that we can do is get out into natural daylight in the morning and throughout the day if possible. Being near windows or doors that let in natural light is also helpful to allow our body to sync itself with the day-night cycle. Avoiding intense light and light rich in the blue part of the spectrum at night and keeping our sleeping environment dark also helps with this.

Sometimes it isn’t possible for us to get as much natural light as we might need. Our modern lifestyles can make it difficult in the winter months to see any daylight. Dull days can limit the amount of light we get too. If we experience Seasonal Affective Disorder (SAD) then we might need more light than others. Bright light therapy devices can be a useful supplement or replacement when we don’t get enough natural light for any reason.

Bright light therapy can also be used to help with challenges we might experience with shift work, jet lag and sleep problems. This kind of intense light delivered at the right time can help shift our body clock so we can sleep and wake when we need to, or adjust to a new time zone .

What is a SAD light?

SAD lights (sometimes known as SAD lamps/light boxes/energy lights) are the most common type of bright light therapy device. They are very bright lights that simulate the level of light you would get on a clear spring morning, which is full-spectrum white light. The devices are specially-made with filters for UV light so that you don’t damage your skin or eyes.

Light intensity is measured in lux. The industry standard is for a SAD light to deliver 10,000 lux at a comfortable distance, although the minimum recommended for treatment is 2,500 lux. Normal light bulbs, or even ‘daylight bulbs’, are not strong enough to treat SAD – 10,000 lux is roughly 20 times brighter than a well-lit office.

Should I speak to my doctor before using a SAD light?

While bright light therapy is safe and helpful for many people, you should always check with your doctor before starting to use a SAD light. Even if you are pretty convinced you are experiencing Seasonal Affective Disorder or Winter Blues, non-seasonal depression or bipolar disorder, your doctor will want to check for and rule out other conditions that might be causing your symptoms. Light therapy is not suitable for everyone, so your doctor will want to discuss this treatment option with you and make sure it’s safe for you to use a SAD light. Ideally, your doctor will supervise your light therapy when you first begin, having regular check-ins with you to see how you are doing with it. I know from personal experience and speaking with many other people that this is the ideal and not necessarily what happens. As with any treatment, pay attention to how you feel yourself, and flag issues with your doctor.

Who are SAD lights not good for/any watch-outs?

Bright light therapy might not be suitable for you, or you might need more careful supervision and additional treatments with it, if any of the following apply to you:

  • You have existing eye problems such as macular degeneration, cataracts, glaucoma or retinitis pigmentosa
  • You have conditions that make your eyes or skin more sensitive to light (photosensitive) such as diabetes, herpes, lupus or a history of skin cancer
  • You take medications or remedies that make you more sensitive to light, for example, certain antipsychotics and antibiotics, or the popular herbal supplement St John’s Wort
  • You experience Seasonal Affective Disorder with a bipolar presentation (you get depressed in autumn and winter but switch to hypomania or mania episodes in spring and summer), or non-seasonal bipolar disorder

If you experience any side effects such as headaches, nausea, dizziness, irritability, or feeling ‘wired’ (like you’ve had too much caffeine), they would usually be mild and go away quickly after you stop using the light. You could try building up your treatment time in 5-10 minute blocks, or sitting slightly further away and using it for a bit longer. Be guided by how you feel.

The main concern that doctors and researchers have had with using light therapy for people with bipolar disorder depression (with or without seasonal pattern) is that they may switch states into hypomania or mania. Research suggests that using a mood-stabilising pharmaceutical together with light therapy can be very effective and used in this way, rates of switching states are low and much less than antidepressant medication. If you and your doctor decide to try light therapy, they will need to make sure you begin with a mood stabiliser for a couple of weeks before starting light therapy and build up gradually. They will need to make sure that you have regular reviews. It can be helpful for everyone if a family member or friend can be briefed to watch out for any switch into a manic state and to inform your doctor immediately if this happens.

When should I use a SAD light?

For most people, SAD lights have their best effect when used in the morning, within two hours of waking up. Some people like to have a ‘top-up’ in the early afternoon if their energy or mood is flagging.

Usually, you wouldn’t use a standard SAD light late in the evening before you want to go to sleep because the light energises you. However, some manufacturers are starting to make SAD lights that add more red and can dim down in the evening, so you have a more versatile light that helps you to wake up and be energised in the morning and to wind down for sleep in the evening. An example is the Lumie Halo, shown in the photo.

For the best effects for people with Seasonal Affective Disorder, most people start to use their SAD light in the autumn months, when they begin to notice the early symptoms of SAD creeping in. Lowering energy levels and increased sleepiness, struggling to get up in the mornings and irritability are often early indicators for many people.

Woman making breakfast in a kitchen with a Lumie Vitamin L SAD light in front of her, receiving bright light therapy while she goes about her day.
Lumie Vitamin L SAD light

From this point, you should ideally use your light every day, at the same time each day until spring. If you don’t use it, the symptoms will usually return within a few days. You might also find that you want to use a SAD light through dull spells at other times of the year, or if you’re working in very poorly lit environments.

For people with non-seasonal depression or bipolar disorder, your doctor will guide you when to use your SAD light. For depression, it would normally be as soon as you notice symptoms and for bipolar disorder depression, you would need to start mood stabilising medication first before you can start using a SAD light (if you’re not already taking one). Your doctor may advise you to use the light closer to midday as some research has shown this to reduce the risk of switching states, while others have shown morning use is fine.

The basic guidelines are a starting point. There has been a lot of research into bright light therapy, but the studies often use different methodologies, so it is difficult for anyone to give exact personalised recommendations.

Added to this, you’re an individual with your own biological make-up, spending time in different environments in different ways. You can get to know your own individual light nutrition needs by paying attention to how you feel and making adjustments to your light therapy until you find what works well for you. Be prepared to experiment and be flexible because you’re working with changing factors – some days are duller than others; you might change your routine or the environments you spend time in; you might be experiencing more stress or not getting outdoors as much due to a hectic schedule. Lockdowns, homeworking and homeschooling are causing many of us to miss out on getting the light we normally would. There are also many other environmental, behavioural and mindset changes you can try that will support your wellbeing – we call this living your light ideal.

How do I use a SAD light?

Position your light around 30 degrees (imagine 11 o’clock or 1 o’clock) at the distance recommended by the manufacturer of your light and switch it on. You can do other activities, like eating, reading, crafting, working or watching TV while you’re having your light treatment. You don’t look directly into the light, it just needs to reach your open eyes. Please ignore any stock photos you see of people sitting or laying like they’re on a sun lounger in front of a SAD light with closed eyes – you definitely need your eyes open! You can wear prescribed glasses or contact lenses, but don’t wear tinted lenses unless advised by your doctor/optometrist that you should, and don’t wear sunglasses or blue light blocking glasses while you have your treatment.

The manufacturer of your light will give you an idea of typical treatment time; for example, the strongest and largest commercially-available lights are generally 10,000 lux and take 20-30 minutes at 35-55cm as a starting point. However, if you have bipolar disorder with or without seasonal pattern your doctor may advise you to build up to this. This is to prevent you from switching states into hypomania or mania. They will usually want to start you on a mood stabiliser before you begin light therapy.

If your light has settings that allow you to use it at different intensities you can select a lower level and have a longer treatment. You can also put your light further away if you prefer that, and have a longer treatment time. Lux drops off significantly the further away you place your light, so if you find you’re not getting enough treatment effect then try moving your light closer if possible, or you may need longer. You can download a free lux meter app on a smartphone and that can help you understand how much light you’re getting and whether you have your light close enough. For an effective treatment for SAD, you need at least 2,500 lux.

How long will it take for bright light therapy to work?

Most people will start to feel better (more energy, improved mood) within two weeks. Many people feel better after only one or two sessions. If it takes longer for you, don’t worry! If you’re not finding the light therapy helpful, try some of the tips here or call the manufacturer for some advice.

If you still find that light therapy doesn’t work for you, try not to lose hope; your doctor will be able to recommend other treatment strategies, such as CBT, antidepressant medication and lifestyle changes.

Which are the best SAD lights to use?

There are a few considerations when buying a SAD light that I have touched on in other answers. The best SAD light for you is the one that fits your lifestyle and preferences best, as well as what you are using the light to do. You might even want more than one for different environments.

For all lights, check that they are medically certified devices and that they have the relevant quality marks for your market (in England, Scotland and Wales from 1 January 2021, UKCA replaces CE for new products). For Northern Ireland it will continue to be CE. They should always have a UV filter and the manufacturer should state the distance at which you receive the light intensity (e.g. 10,000 lux at 30cm).

I personally use and recommend buying direct from Lumie – they have been light therapy specialists since 1991, have a long history of research and development in light therapy products, offer trial periods when you buy directly from them and good warranties for all products. I have used their products since 2004. I don’t have any commercial agreements with them and Make Light Matter doesn’t either – I just value their work and they have been supportive of mine.

Treating SAD?

If you have Seasonal Affective Disorder with or without a bipolar presentation, then you will need to use the light every day for about five months of the year when you would usually experience depressive symptoms. A fast treatment time might be your priority and it is more important for you to get proper treatment, as you’re not just using the light for a general energy boost.

SAD researchers recommend a large box with full-spectrum (white light) fluorescent tubes because these are the type that they have done the most research on and have been shown to be the most effective and safe. The best large lights will allow you to get 10,000 lux at a comfortable distance (30-55cm). Their size means that small movements of your head won’t disrupt your treatment, unlike it can with some LED lights. They can also be more comfortable from a glare perspective because you’re not trying to get a narrow beam of light to reach your eyes; it’s a much broader spread of light.

Need portable bright light therapy?

As LED technology has progressed, manufacturers have started to incorporate it into their SAD lights. There is a little research that shows that LED can provide effective bright light therapy – they are sometimes known as beam devices. These are usually smaller, lightweight and use less energy. If portability is important to you, you’re treating the milder Winter Blues form of SAD, just wanting an energy boost or to help with jet lag, then these might be ideal for you. They can also be great to use as secondary lights if you normally use a large fluorescent light at home and need to travel, or want a second light at work for top-up treatments.

As with all lights, you will need to follow the manufacturer’s recommendations on the distance to put your light at to get the full light intensity (e.g. 10,000 lux at 16cm). Steer clear of any that don’t state this in their advertising. I have seen some LED SAD light descriptions that say they give you 10,000 lux at 10cm, which is less than the length of my thumb to my wrist for some context. For most people, this would be impractical and uncomfortable and so you would put the light further away, which would mean you would need a longer treatment time than stated. With LED devices you also need to be a bit more careful with their placement and to keep your eyes in the same place where the light is reaching them – turning your head might mean that the light isn’t properly reaching your eyes.

Some manufacturers will state that their LED lights are ‘blue-enriched’ – usually this means that the lux level will be less, but they have used more of the blue part of the light spectrum in their light, which is shown to be the most effective at suppressing melatonin (the hormone that makes you sleepy and keeps you asleep), boosting the neurotransmitter and hormone serotonin (has lots of functions including mood regulation) and cortisol (a hormone that helps you feel alert).

Some manufacturers have even produced blue-only lights – these are not recommended in a recent Yale study of commercially-available lights in the USA, due to concerns about the potentially damaging effects of too much blue light on the eyes. Full-spectrum white light has the most research into its safety and effectiveness.

There are also other formats of bright light therapy available that you could consider such as a visor, glasses or headsets.

Lumie Vitamin L is portable so can go to work with you

How much does it cost to buy and run a SAD light?

Prices vary hugely for a SAD light and the market has been flooded with products in the last few years. It can be difficult as a consumer to know whether a £25 LED light is going to do the same job for you as a £150 fluorescent light. For a quality light box that is an approved medical device and has been clinically tested, you can expect to pay £75 to £150 or more at full price. If you have a light with fluorescent bulbs, they will need replacing every few years, depending on how much you use the light and they’ll be around £10 to £15 each.

Energy-wise, even the most powerful fluorescent light box I know of (the SAD Lightbox Co. Diamond 5 that uses five 36W tubes and takes 20 minutes for treatment at 55cm) will use just over one pence per treatment. A 3 x 36W box like the Lumie Brazil, used for 30 minutes at 35cm will use less than a penny per treatment. This is based on £0.17 per KWh – the UK average energy price per KWh for 2020.

You can work out the rough cost of light therapy per treatment day, which is how I think of this investment. So, for example, the Lumie Brazil costs £150 and it’s a good quality product that will likely last you 10 years at least. Say that you replace the tubes a couple of times at around £12.50 a tube (3 tubes x £12.50 x 2 times) = £75. You use the light every day for five months of the year (typically how long SAD lasts) =152 days a year or 1,520 days in a decade. The product is £225 in total and you spend a penny a day for the energy (£1.52 a year or £15.20 in a decade). Over a decade the cost is £240.20, which averages out at £0.16 per day.

In your first year, the initial cost of the light makes it more expensive per treatment day, but this drops over the 10 years. I have illustrated this in a table, which I hope you’ll find helpful:

YearProducts boughtCost for productsCost for energyYear total costYear cost per treatment day (152 days)Total running cost since startNo. of treatment days since start (152/year)Total running cost per treatment day since start
1Lumie Brazil light£150£1.52£151.20£1.00£151.21152£1.00
2£1.52£1.52£0.01£153.04304£0.50
3£1.52£1.52£0.01£154.56456£0.34
4£1.52£1.52£0.01£156.08608£0.26
5Replacement tubes x 3£37.50£1.52£39.02£0.26£195.10760£0.26
6£1.52£1.52£0.01£196.62912£0.22
7£1.52£1.52£0.01£198.141,064£0.19
8£1.52£1.52£0.01£199.661,216£0.16
9Replacement tubes x 3£37.50£1.52£39.02£0.26£238.681,368£0.17
10£1.52£1.52£0.01£240.201,520£0.16
Worked example of costs for buying and running a SAD light over a period of 10 years (numbers are rounded and for ease, fixed energy costs based on 2020 average cost)

I know that the initial outlay can put many people off getting a SAD light – it can feel like a risky investment if you don’t know if it’s going to work for you. Read a few reviews, and you’ll see many people saying they wish that they had bought one sooner, rather than continuing to suffer with SAD symptoms year in, year out. This is why some manufacturers will offer you a money-back guarantee. For example, in the UK, if you buy direct from Lumie, they give you 45 days to try the product and you can return it if it isn’t suitable for you. You may also be able to pay in three instalments with Klarna where this is offered.

Alternatively, you could try buying a second-hand SAD light and then the investment will be less. However, bear in mind if you buy a fluorescent light that you may need to buy some new bulbs, which could make it less cost-effective to buy second-hand.

Where can I buy a second-hand SAD light?

Second-hand, used SAD lights are sold on Ebay, Shpock, Gumtree, and Facebook marketplace.

Lumie Halo in daytime mode

Which are the most environmentally friendly bright light therapy devices?

LED lights win hands down on environmental considerations. They will use less energy than fluorescent lights and are often smaller, so lighter to deliver with fewer deliveries needed. You also don’t need to replace tubes, so they don’t need to be stored. At the end of their life, some LED lights can be recycled, where the facilities exist.

Does anywhere refurbish or fix SAD lights?

Lumie sometimes offer refurbished lights at a discount and with their same warranty and trial period. Your manufacturer may fix lights under warranty – check your paperwork. For older lights, we are not aware of any specific company that will repair a SAD light. You could try your local small electrical repair shop (outside of lockdown).

How do I dispose of a SAD light?

If your light can’t be fixed or it isn’t economical to do it then you will need to dispose of it properly according to the Waste Electrical and Electronic Equipment (WEEE) guidance. You will also need to dispose of any bulbs using the same guidance. You can usually do this at your local household recycling centre, where they will have clearly marked areas. Check Recolight for your nearest centre and helpful advice.

What are the drawbacks of bright light therapy?

Bright light therapy for most people is a safe, effective treatment. It won’t be suitable for everyone, though, which is why you should check with your doctor before starting to use a SAD light or any other form. Some of the drawbacks for people who do use it can include:

  • If you’re using it to treat SAD, you will need to use light therapy every day from the time your symptoms start until they usually go away – if you don’t use it then your symptoms return quickly
  • You will need to consider how to fit your light treatment into your daily routine, which can be challenging if you don’t have much routine, find it difficult to stick to one, or you have to leave home very early and don’t want to get up any earlier
  • Some people find that they start to feel negatively towards the light therapy routine, or the SAD light itself – like they’re ‘shackled to this box’
  • SAD lights aren’t currently available on the NHS in the UK – some people are unwilling to risk the investment for something they don’t know will work for them – and some people can’t afford to pay for a light themselves

You may be able to overcome some of these with planning, considering where and when you’ll use your light. This might determine your choice of light therapy device. What will you do while you have your therapy? What will you do if you travel? Could you use a light at work? You might find it helpful to consider your light treatment as self-care or ‘me-time’ and use the time to catch up on your favourite YouTuber or podcast, do some reading, gaming, crafting, manicure your nails, journalling or other personal development, for example. Some SAD light manufacturers offer a money-back guarantee, which allows you to try the light out and return it if it doesn’t help you. You might also be able to pay in instalments or buy a second-hand light.

Can a SAD light boost my Vitamin D level?

That would be great, but no, unfortunately a SAD light can’t help you to avoid the Vitamin D deficiency that many of us experience in the UK’s autumn and winter months. All medically-approved SAD lights filter out UV light. You can get Vitamin D through your diet (oily fish, egg yolk, red meat, liver, fortified foods) and by taking a supplement from October to March when we don’t get enough Vitamin D from the sun in the UK.

What other types of light therapy are there?

You can also get bright light therapy in the form of a visor, or glasses that you wear, so you can move around while receiving your treatment. I haven’t tried these personally yet, but have been told by other people that they work well for them. Also, the HumanCharger® (formally Valkee) was launched in 2007. This headset delivers light to the brain through your ears. The company recommends the headset for general energy, helping with jetlag and Winter Blues, but doesn’t claim to be able to treat SAD. I haven’t had any feedback from anyone that has used one of these and I haven’t seen any research that proves its effectiveness. I’m interested in hearing from anybody that has!

You may also have heard of or seen dawn simulators or wake-up lights. These are alarm clocks that wake you up with light and they are not intense enough to treat SAD, but are a useful device for helping anyone to get up in the mornings (or other times if you do shift work). Some manufacturers have started to combine their wake-up lights with SAD lights – for example the Lumie Zest. These devices are small and might be good for you if you intend to stay in bed for a while after waking, or for travel. You would need to ensure the light is reaching your eyes at the right angle when using it for your bright light therapy.

Other types of light therapy that use different parts of the light spectrum have been emerging that help to treat skin conditions and the beauty industry has started to introduce products and services for anti-ageing and improving the look of skin.

Tanning beds and booths are not recommended for treating Seasonal Affective Disorder as they expose your skin and eyes to harmful levels of UV light. Medically certified SAD lights filter out UV light.

Anything else?

I hope that you have found this article helpful, but as always, I welcome your feedback and comments. Is there something that you wanted to know that isn’t answered here? You can email me or comment below.


Image credits and notes

Thank you to Lumie for providing images of some of their products for our use. We don’t have a commercial relationship with Lumie, but the team has been very supportive of Neina’s work over the years as Little Light Room and Make Light Matter. This article originally appeared on Neina’s Little Light Room blog, which has since evolved into Make Light Matter.

4 thoughts on “Bright light therapy guide”

    1. Hi Rowan – thanks for your question.

      If the room is small it would make the whole room brighter I’d say, because the light would bounce off of nearby walls if they’re light-coloured. If it were a bigger room, it would make the area around it brighter, but as you moved away it would have less effect. Does that make sense? x

    1. Sorry for the late response – your comment got caught up in my spam folder! Thank you! Hope you’re getting some sunshine over there!

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