Full spectrum (daylight) bulbs - LED vs Tungsten

You can get 90 CRI fluorescent tubes (not the cheapest) and LEDs (ditto) that colour temperature is generally called "daylight" white.

Don't know how special SAD lighting is, I thought it was high intensity, possibly with a touch of snake oil?

This anecdotal article in the Grauniad from a SAD sufferer might be worth what you pay for it:

David snipped-for-privacy@btinternet.com wrote

I just take vitamin D pills and avoid listening to labour politicians. Or the BBC. Or reading the Guardian.

I win a bet with myself as to the content of a posting from your good self ;-)

I'm no expert and haven't researched the subject but an elderly relative has suffered from this (plus other complications) and is now blind in one eye and with limit vision in the other. In mid stages a pair of orange tinted glasses were provided by the RNIB (Royal National Institute for the Blind) which helped a lot with vision. Unfortunately the supplied glasses were somewhat of a industrial design and I found an alternative amber pair of safety glasses which were much lighter and worked just as well. Similar to

Unfortunately on social media and in some self help groups the same "urban myths" are constantly repeated and with no studies referenced to back up claims.

Even when researching on the web be careful with USA sites selling snake oil alternatives that are cheaper than effective drugs for those without medical insurance. I've found the NHS web site pages to be more informative about medical conditions, common medication and for advice on how the condition may advance.

Somewhat less industrial looking:

What my relative found was the glasses needed to exclude daylight creeping in at the sides of the lens so excluding the traditional glasses design. The ones I linked were a near perfect fit over the eye socket and extremely light

There were several on that Amazon page with yellow side panels. Also, I wasn't clear if your relative has to wear other glasses as well. Some of those on the Amazon page are meant for overfitting ordinary glasses.

Congratulations.

It is amazing how much stress the MSM will put on you.

Even the right wing parts.

I believe the white LEDs are quite good now, but they all still produce a spiky spectrum. Both coloured LEDs and the 'white' phosphors radiate single lines in the spectrum, and phosphors are a mix of chemicals to produce a reasonable spread of wavelengths.

For colour perception, the eye is easily fooled, and TV sets use LEDs or filters of just three colours to generate a wide range of perceived colours. Good colour rendition of every object seen means that the light source needs to produce wavelengths that are reflected well by the objects being observed, something which is only ever approximated by light coming from non-incandescent sources. The more phosphors, the better the wavelength spread with 'white' LEDs, the better.

Only light produced by incandescence (i.e. heating things) produces a continuous smooth spectrum. The colour temperature is the temperature of a physical object which produces light simply be being extremely hot.

"Warm" light is of that CT order. Film and TV standardised on light of that colour because tungsten lamps run at around 2700K and tungsten halogen at around 3000K.

Sunny daylight is around 5600K most of the day, and much redder at dawn and dusk, perhaps as low as 2000K. Cloudy daylight is actually higher, at around 6500K. Back in the days of CRT monitors, phosphors and adjustment were specified to produce a perceived white of around this colour temperature from broadcast monitors. I don't think TV manufacturers worry too much.

Broadcasters have been using LED lamps for many years, normally containing three monochromatic LED colours. Since the camera sensors pick up light filtered into three colour bands, the light spectrum doesn't need to be continuous.

What seems to be required here is a light without too much blue, and I would have thought that modern LEDs described as 'warm', or with temperatures over the 2700-3000K range should be OK. Nobody is going to put blue phosphors into a lamp if they are not specifically needed.

I always understood - I cannot say I am that interested - that the 'medical' aspects of daylight were all about UV and the blue end of things.

White skin and blue eyes are an evolutionary response to low levels of sunlight.

Vitamin D pills are a cheap and simple way to ensure adequate vitamin D even if you don't like oily fish...

The use of LEDS which by and large do not emit in the UV spectrum is a bit moot.

Generally vitamin D pills are cheaper.

You can by 'tanning lamps' though.

D2, especially in us old 'uns, can be worse than useless. D3 with K2 is good - the K2 acts as a sort of 'adjuvant' for the D3.

Astonishingly, I was driving into town today, in very (VERY!!) bright sunny weather, sun low in the sky even at 1300, and I wondered if "those yellow glasses" would help me ("Get yours at the checkout NOW!") I had a bad retinal detachment last year, and that eye has been bad ever since, and suffers badly from glare/excessive brightness; my compensating left eye suffers too (_and_ it's developing a cataract!).

So I tune into uk-d-i-y this evening, and here is this discussion! Thanks for raising it Dave R, and to everyone else for the useful links!

Now see my other post ("Headlights: more light, less illumination") very much on the same subject, but very much more universally applicable!.

Cheers all Another John

If the sun is low and the road surface at least a bit reflective, then polaroid glasses or clip-ons should help a bit. The shallower the reflection angle, the more polarised the reflected light becomes.

It appears that the recommendation is not to wear yellow glasses for driving as they don't reduce glare.

I mentioned them for helping someone with later stages of AMD who would likely banned from driving.

France used to insist on yellow headlights to reduce glare, until it was demonstrated that it didn't, it just reduced the light level.

Alternatively, get rid of the cat and get a dog. Four+ walks a day will be more effective than quack remedies and its (possibly) a lot cheaper than fat-jabs.

If only I could...