Further information on light and darkness

The Biological Clock Website
A resource for chronobiology.

The Nature of Light and Colour
Good overall article by the camera manufacturer Kodak.

Morningness-Eveningness Questionnaire
This will help you assess your natural sleep pattern and when you should use light therapy to treat it, although take this last part with a pinch of salt unless you only need less than seven hours of sleep.  It also provides information that will be useful when considering darkness therapy.  The main website is rather strongly biased towards the products it is selling, but this questionnaire is excellent.

Bipolar Disorder, Light and Darkness
An excellent overview of light and darkness therapies, which also discusses various products in an unbiased fashion.  It is aimed at bipolar disorder in particular but mentions sleep a few times and is the best site I know for helping you understand how this all works.  The author, Dr Jim Phelps, is a respected psychiatrist and specialist in bipolar disorder.
Primarily an excellent resource on how darkness therapy works and its different applications, including many research abstracts.  Also sells products (see below).

The Photoperiod Effect
Rather more radical website on darkness therapy, which claims that low melatonin levels are at the root of many common illnesses such as cancer and diabetes, and also less common ones such as Ehlers-Danlos Syndrome (which the author has himself).  Advocates a more extreme version of darkness therapy using complete darkness with only occasional use of dim red light.  The most extensive discussion of darkness therapy that I have found.

Further information on ME/CFIDS

The ME Association (UK support charity)
Action for ME (UK support charity)
SupportME (UK support charity)
ME Research UK (UK research organisation)
Alison Hunter Memorial Foundation (Australian research organisation)
Phoenix Rising
(good personal website)
CFIDS Community Advisory Bulletin (collection of various ME/CFIDS sites)
Dr Myhill (I am leaving this link up as Dr Myhill, who claims to specialise in ME/CFIDS, is controversial and some people may find certain aspects of her website useful.  She has been repeatedly investigated by the General Medical Council and they have limited her ability to practise medicine and told her to take down certain portions of her website.  However, her articles on sleep were not targeted, and there is still some useful information in there.  Approach with caution.)

Further information on sleep disorders
Information on Delayed Sleep Phase Syndrome. Sleep
Information on a range of sleep disorders.

Circadian rhythm disorders
This page discusses circadian rhythm disorders and illustrates them with sleep charts.

Circadian Sleep Disorders Association
This website is still under construction, but it has some information, a printable sleep diary, a good links section, and a link to the Nite-Owl e-mail list.

Workplace Accommodations for Individuals with Sleep Disorders
American website discussing this topic as it relates to the ADA.  Useful for both employers and employees.

Further information on other medical conditions

Meares-Irlen Syndrome (visual processing disorder, usually treated with colour)

Light therapy device sellers in the UK

Manufactures and sells lightboxes and dawn simulators.  Only sells their own brand products, but has a fairly good range for a single manufacturer and offers a generous free trial period for lightboxes (pay upfront but get a full refund at the end), which is 30 days, although they will extend it to 6 weeks for ME sufferers.  You can try out their other products too, but there is a restocking fee, £10 for dawn simulators and £15 for light visors.  The dawn simulators are all-in-one units only.  Their research page is very helpful, linking to a number of research abstracts on various applications of light therapy.  Fairly good on sleep disorders.  I would start here only because of the free trial period, otherwise go to the National Light Hire Company as it has a wider product range.

The National Light Hire Company
Sells a variety of lightboxes and dawn simulators by different manufacturers, including all the major manufacturers, a combination bright lightbox/dawn simulator and also the Sleeptracker wrist device.  Has a very large range and can advise on the best product to use.  Hire-purchase system for lightboxes available.  Lightboxes are categorised under SAD Light Boxes, and dawn simulators under Sleep Products.  Light therapy is the main focus of the company.

Sunrise System
Manufactures and sells various different types of dawn simulators, including all-in-one models, models which plug into a lamp of your choice, and a combinaton bright lightbox/dawn simulator.

SAD Lighting
Nice little company selling a good range of lightboxes and dawn simulators.  No free trial or hire-purchase, however.

Allergy Matters
Another well-known UK retailer, with a wide range and a good information page on light therapy.

Light therapy manufacturers in the US

Philips now makes the GoLite as well as an all-in-one dawn simulator using fluorescent light, the Wake-Up Light.  Philips is an international company, and their products can be bought from a wide variety of sellers worldwide as well as directly from them.

Darkness therapy product sellers in the UK

Optima Low Vision
Sells a wide range of anti-glare filter spectacles, both fitover and non-fitover.  You want to make sure that the glasses you choose are marked as blocking 100% of blue light, and are either amber, brown, red, yellow or orange.  Remember that colours will look more natural through brown but you’ll also need a darker tint, that red will make everything look monochrome, and that yellow apparently increases contrast in a way that some people find glaring, so personally I recommend orange.  I have only tried one of the cheapest pairs of fitover glasses and found them uncomfortable, but there are many others to choose from.  They are likely to be huge and not look terribly pretty, but they should do the job.  Postage and packaging is free as these come under the umbrella of “articles for the blind”, whether the customer is blind or not, so if you try them and don’t get on with them, you won’t lose any money.

Optical Express
This is for having tinted prescription glasses made up.  Probably any optician’s will do, this just happens to be my local one and they did a good job at an excellent price (I paid £61).  They have a nice range of frames starting at low prices, and if you explain that you need a frame that will cut out as much light around the edges as possible, they’ll help you find something.  Getting the right colour tint is trickier, they don’t offer orange as standard, but a couple of phone calls to the head office sorted that out and it’s the same price as a standard tint.  Ask for 500 Orange 50%, and make sure it’s put into special instructions for the job order.

Probably the cheapest place to buy yellow light bulbs if you can’t pick them up locally.  Make sure that the coating on the bulb appears opaque when the bulb is not turned on, rather than the translucent sort where you can still see inside the bulb.

Formatt Filters
Sells lighting gels which can be used as computer screen filters, and if you ask nicely may send you a couple as a free sample.  I have a 17″ widescreen laptop and could probably have cut two screen filters out of each sheet.  Unfortunately I don’t remember which colour it was, and they sell hundreds, so you’ll have to pick out something in the amber or orange line and hope for the best.  It’s quite a strong orange.

Darkness therapy product sellers in the US
Sells a range of yellow light bulbs (including nightlights),  orange monitor filters and some rather expensive blue-blocking glasses, both fitover and non-fitover.  I have not personally tried any of their products.  They seem to know what they’re talking about, unlike whom I would recommend avoiding.

Places to buy other useful things

Tinnitus section of the online shop for the RNID (Royal National Institute for Deaf People).  Tinnitus relaxers, also called white noise generators, are very useful if you are being kept awake by tinnitus or external noise.


Circadian Rhythm Disorders Forum on
Includes a weekly chat

Sleepnet forum

Sleep Disorders forum at
This website also has sleep tracking software

Other sleep bloggers

Everything You Always Wanted To Know About Sleep (But Were Too Afraid To Ask)
Article in a science blog discussing chronobiology.

The Sandman is from Mars: Defeating the Non-24 Sleep-Wake Syndrome
Personal blog written by someone who is successfully treating his Non-24 Sleep-Wake Disorder using the same methods as me.

DSPS, A Sleep Disorder
Two WordPress bloggers who have DSPS and Non-24 Sleep-Wake Disorder.

Sleep Well and Live
General WordPress blog about sleep with a focus on sleep apnoea, sponsored by the Sleep Wellness Institute.

Sleeping Well
WordPress blog with tips for good sleep, with a particular focus on bedding.

Sleep Doctor
Blog written by a sleep specialist.


This freeware makes the color of your computer’s display adapt to the time of day, warm at night and like sunlight during the day.

2 Comments on “Links”

  1. isochroma Says:

    To achieve zero circadian stimulus, the monitor must completely zero both blue and green channels. f-lux doesn’t do that. My batch file does 🙂 But it only works for Nvidia cards.

    Red Only:

    rundll32.exe NvCpl.dll,dtcfg set_normalize_brightness 0 green 0.0
    rundll32.exe NvCpl.dll,dtcfg set_normalize_brightness 0 blue 0.0
    rundll32.exe NvCpl.dll,dtcfg setcontrast 0 green -82
    rundll32.exe NvCpl.dll,dtcfg setcontrast 0 blue -82

    Restore to normality:

    rundll32.exe NvCpl.dll,dtcfg set_normalize_brightness 0 green 0.5
    rundll32.exe NvCpl.dll,dtcfg set_normalize_brightness 0 blue 0.5
    rundll32.exe NvCpl.dll,dtcfg setcontrast 0 green 0
    rundll32.exe NvCpl.dll,dtcfg setcontrast 0 blue 0

    • I know f.lux is only partially helpful, and to be honest I think it’s more useful for lessening eye strain and serving as a reminder that lights should be lowered in the evening. I do notice that the screen isn’t as bright even through my (perfectly adequate) orange glasses, and I find it more comfortable on the eyes in the evenings. It won’t stop you from being kept awake by the blue light if that’s all you’re using for that purpose. I’m hoping that the people who created it will produce an updated version where you can darken the screen more completely.

      Thanks for the instructions, but I’m not quite sure how to follow them! I don’t think I have an Nvidia graphics card either. Could you tell me more about how this works? Are you sure that green needs to be completely gone as well? Doesn’t this make the screen well-nigh impossible to read?

      There are programmes such as Musatcha which will alter the screen appearance, but I don’t like them as they put an overlay over everything, dark as well as light, and thus reduce the contrast to the point where I give up trying to read the screen after a few minutes.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: