Blue light and the retina
@elisadelina yea no f.lux is wrong on this matter. The frequency / quality and source of the light is massively important.
@yourmom We're referencing doses of blue light from the international hazard documents (e.g. IEC 62471, ICNIRP, and ANSES). There is a broad consensus regarding these doses of visible radiation, so if you're saying you disagree with that body of research, please elaborate.
There is indeed a lot of marketing that ignores dose and focuses only on wavelength. This approach is incorrect - there's a threshold of energy known to cause harm to the human eye. Light is measurable and quantifiable, and if you don't have enough energy to damage cells, you don't have enough energy to damage cells.
The potential blue light hazard from the brightest computer monitor we know is less than 10% of what you'd see from just blue sky, removing any direct sunlight. If you were to look at a regular sidewalk in daytime, that exposure is hundreds of times more powerful than your monitor screen - this is how we are hoping to get people to think about light, in real power units and not just subjective colors.
@lorna I get all that, I disagree I think the flicker rate of the source of light (artificial light ) and the overall spectrums balance with other colors is what makes the real difference. Not the intensity in terms of power units or specific wavelengths. The most intense of blue light is always balanced by red in the sun's light. It changes the effect on physiology of the retinohypothalamic tract, the setting of superchiasmatic nucleus circadian rhythm and all the downstream molecular clocks of our organs.
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@yourmom I think you owe the thread some clear language here - you began by saying "f.lux is wrong", and you have made no statement at all that could support this position.
f.lux launched nearly nine years ago, and the hypothesis behind the product is that displays make enough light to disrupt circadian rhythms at night. We understand these biological systems and the research behind them very well, and we have helped to popularize the research on the non-visual effects of blue light and its effects on the central clock, the SCN. As well, we frequently criticize flicker and distribution of light that leads to glare.
A majority of the non-visual effects of light are conveyed to the SCN through a single photoreceptor, and a non-visual system that achieves the "balance" you refer to is not supported by any literature. Even though the cones are believed to convey extra information to the ipRGCs, they are doing so using much of the same circuitry that drives color perception, not by some magic additional system.
I have previously made notes about the claims made about beneficial effects due to IR and the retina here: https://forum.justgetflux.com/topic/3809/which-is-the-best-light-troughout-the-day-to-stay-in-front-of-pc/6
And again, I will say, the evidence in rodent studies suggests that these effects happen only at extreme irradiance levels, many hundreds of times greater than indoor lighting
It is very reasonable to talk about what you see (these colors don't match) or how you feel (this flicker makes me feel eyestrain), but to impute physiological harm (as some do) to these effects without any evidence is a mistake. Some things are just uncomfortable, but they are not known to cause any lasting harm.
We are facing a similar problem with circadian effects - people believe, falsely, that changing color temperature a little bit will positively affect circadian rhythms, when in fact, small changes are likely to have very small effects. Eye strain and circadian/alerting light are not likely to be the same thing for most people.
When you are talking about non-visual physiological effects of light, you can't perceive directly everything that is going on. Dose matters and measurement matters, and you would be well served to read up on both.
@herf Your so close to completing getting it. I'm well read on the subject. It would be foolish to get emotional bout it. So lets just clarify a bit bout ipRGCs.
Intrinsically photosensitive retinal ganglion cells (ipRGC) and their connection with the suprachiasmatic nucleus ( circadian rhythm center )
There is a third type of cell in your retina called the intrinsically photosensitive retinal ganglion cells abbreviated ipRGC’s. These cells utilize a different photopigment called melanopsin, are much less sensitive to light, respond to light slowly, have far lower spatial resolution. Although these cells do have some role in vision / motion detection / brightness detection their primary function is signaling ambient light levels (irradiance) to the brain.
ipRGC’s express a melanopsin allowing them to directly respond to light, and they send axon projections to a brain target known to be involved in circadian photoentrainment and photic suppression of pineal melatonin release. The main center involved with the photoentrainment aspect is the Suprachiasmatic Nucleus (SCN). The ipRGC directly sends out a ton of axons to the SCN indicating its pivotal role in circadian rhythm management.
Daily rhythms in mammalian physiology and behavior, collectively called circadian rhythms, are controlled by a tiny cluster of cells in the SCN of the hypothalamus. SCN neurons possess a transcription/translation-based molecular clock that allows them to autonomously regulate activity patterns in near 24-hour rhythms, the SCN must be reset periodically so that circadian rhythms are synchronized (or “entrained”) to the light/dark cycle. Light is by far the most potent circadian entrainment cue, and ipRGCs are the primary cells that carry this signal since eliminating these neurons abolished photoentrainment in mice (Hatori, 2008; Goz, 2008; Guler, 2008).
The reason f.lux is good is because you can run it on red all day. Blue light will turn out to be the most harmful of all non-native EMF. Unbalanced blue is massively important when it comes to the timing of all your bodies systems and I'm not just talking about the eye's / dopamine overuse / melatonin production inhibition. Great poinnt about the rats/ IR into the retina and your right it was way above indoor light levels. You know whats way above indoor light levels. The outside world, more than any app, making sure your skin and retina's get exposure to unfiltered am sunlight is critical
I am literally facepalming right now.
@lorna continue in fact don't stop , keep facepalmed permanently. lol
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@yourmom Some online gurus (the ones I suspect you're reading) start with real science, and indeed, the basic circadian research is supported by thousands of studies. You can cite that all day - we know all the references too.
The trouble is when an online guru is your sole source of information, you don't realize when it has gone off the tracks into a place where the science doesn't exist. "the most harmful of all non-native EMF" is simply BS, and you're not citing a dozen studies there, because they don't exist.
There is no "unbalanced" blue like you're describing. Lighting that matches daylight spectrum for all known photoreceptors, seen at indoor levels (100x lower than outdoor light) is not known to harm the retina. There is just no literature that supports this, and you're listening to the wrong people if you believe it.
@yourmom I'm going to go enjoy my Sunday now, and I hope you do the same. Take a nice long walk outside. your lateral geniculate nucleus will thank you.
so do I understand it right, that being in front of a computer screen all day (for example 14+ hours) is perfectly safe and does not permanently damage eyes ? And even if blue light caused any permanent damage, then one hour walk would in fact be more harmful ?
@Muden Regarding the amount of light that reaches the retina: five minutes outside in the sun means more blue light (and more light of all wavelengths) reaches the retina than hours in front of a computer screen.
I personally would not recommend to anyone to stare at a computer screen for 14 hours a day, but giving medical advice is beyond the scope of this forum.
Questions about computer screens and how they can affect your eyes are best directed to an eye doctor who has examined you in person.