Light Therapy Part 1 – The lightbox

Light therapy is one of the first tools to work with when dealing with SAD but what does it do and how does it work?  To start with the best thing is to understand what Circadian Rhythms are.

Your Circadian Rhythm

All forms of life are affected in some way by the rising and setting of the sun.  Watch a daisy through the day and you will see it open at dawn and close at dusk.  We are just the same but the changes are harder to see.

As the sun sets our brain starts to produce sleep hormones and when levels reach a certain point we become sleepy.  As the sun begins to rise this production stops and we wake up.  In the summer this generally isn’t a problem as we make the most of the long days but as light levels drop as we move into Autumn those of us with SAD can experience increased fatigue, lethargy and brain fog due to continued production of these sleep hormones.  If we ignore these signals I believe we go on to experience anxiety.

Faking a sunny day

When we find that we are struggling to stay awake or our brains seem not to work we can fake a sunny day using lights.  Some people find that simply having brighter bulbs in their rooms helps enough but for most sufferers proper SAD lights need to be bought.  These are known for being expensive but they are actually coming down in price, particularly in the UK.

The criteria for an effective SAD light are that it must be 10,000 Lux, which refers to the brightness.  It appears that full spectrum is not necessary but it must be UV shielded.  Lights are available with fluorescent style bulbs or, more recently, LED and blue lights.  It is also important to bear in mind that the “lux” level tails off as you move away from the light.  This means that although some lamps may state that they are 10,000 Lux is it possible that this is only at a distance of a few inches away from the light.  This makes these lights quite unusable as you need to have them on the end of your nose for them to be effective.  As a rule of thumb buy as big a light as you can find.

When first looking into light therapy you will also find sunrise lamps, also known as dawn simulators, available.  These serve a different purpose and I cover them on the Light Therapy Pt 2 page.

Using your lightbox

“I actually cannot get over how much my light box has helped me so far this winter.” – Angie

Once you have bought your light you need to work out how to use it is best for you.  There are 2 steps to this process.

To start with it is important to understand what the light will do.  If you use your light correctly it will halt the production of sleep hormones in the brain.  For most people this means it is necessary to use their light early in the morning.  However, some people find that is also useful to use it in the early evening too.  What you must not do it use your light too late in the evening.  Your brain takes time to build up enough of the sleep hormones; you will not be able to use your light at 10pm and expect to be sound asleep by 10.30pm.

Once you understand this process there are a couple of websites that can help you work out what is best for you.  The first is the CET Morningness/Eveningness Test and the second is the Philips Circadian Rhythm Test.  These tests are a great starting point in understanding when you should use your light.  You may find that the recommended time is far too early in the morning for you.  My suggestion here is to use it as early as possible and if necessary work your way towards that time.

 Most people use their lights for 30 minutes but you might find that the effects don’t last long enough.  This is where listening to your body helps.  I personally have found I need some kind of light all day if I need to keep my brain functioning.  I have invested in a large 10,000 lux lamp that I use first thing in the morning and then when I am at work I have a smaller, probably 2,500 lux lamp that I use all day up till 5pm.


Some people find that they get a headache when they first use their lights.  If this happens start by using it for 5 minutes at a time and sit further away.  As the days pass start to sit closer then increase the amount of time until you are able to use it for 20 to 30 minutes.

When you first start thinking about using a light it can seem quite daunting to find time to use it.  I think the trick is to find ways you can fit it into your normal schedule.  I have my large light in front of the sink and I do the previous night’s dishes in front of it.  I then eat my breakfast and make my lunch for work with it on.  Other people have their light by the bed, wake up 30 minutes earlier then spend the time before they get up reading or catching up on e-mails before they get up.  When you have found how much of a difference it makes you will be looking forward to using it.