Name: Artificial Light vs Sunlight: A Substitute, Never an Equal
Creator: Realised
Published: 2026-06-01

Summary

Artificial light is a substitute for sunlight, never an equal — sunlight is full-spectrum (UV, visible, and roughly half near-infrared) and orders of magnitude brighter, while LED and fluorescent light is blue-spiked, UV-poor, near-infrared-poor, dimmer, and often flickering — so the honest move is to get real daylight when you can and mimic its day-bright / night-dim pattern with artificial light when you can't, while keeping the genuinely-superior claims (spectrum, intensity, UV-mediated physiology) firewalled from the wellness overclaims (that "junk light" damages your retina or causes dise

Why Strong

Strong Evidence because the entry's load-bearing claim is the substitute-not-equal thesis and the day/night-pattern prescription, both of which rest on settled physics (solar spectral composition, illuminance facts) and well-replicated circadian science (evening room light suppresses melatonin; bright daytime light improves alertness). Several embedded nodes are independently strong: the intensity gap, the UVA-nitric-oxide and beta-endorphin physiology, and the ophthalmology consensus debunking the retinal-damage overclaim.

NOT Foundational because it carries genuine clinical and commercial judgement and a two-sided controversy, not a single undisputed axiom.

NOT Moderate for the headline, because the spine of the entry is not "a few suggestive studies" — it is settled physics plus replicated circadian findings. Only specific downstream sub-areas sit lower, and the entry marks them rather than inheriting their uncertainty.

The per-sub-area split (read this, not just the headline):
• Circadian and blue: Strong — best-evidenced sub-area (Gooley 2011, Smolders 2012, Cochrane). Melanopsin entrainment is settled.
• Intensity and spectrum: Strong for the physics (illuminance and solar-composition facts); the inference that spectral truncation harms you is Emerging.
• Near-infrared and mitochondria: SPLIT — the photobiomodulation mechanism is Strong-to-Moderate; narrow therapeutic uses are Moderate; indoor-deprivation-causes-disease is Emerging-to-Experimental. Do not conflate the three.
• Flicker: Moderate for the susceptible minority; Experimental for any "harms everyone" generalisation.
• Retinal harm: Strong debunk — the damage claim is an overclaim; the circadian claim is separate and survives.
• UV-mediated uniqueness: Moderate-to-Strong (UVA-nitric-oxide, beta-endorphin, vitamin D).

Practical takeaway

The framing to hold: sunlight is the real thing; artificial light is a stand-in. Use the stand-in well, never confuse it for the original.

Get real sunlight first.
• Get outside in daytime, especially in the morning, ideally without sunglasses or a window between you and the sky — even an overcast day vastly out-brightens indoor light. The free morning-light habit is owned by morning_sunlight_exposure; route there for the protocol.
• Treat real daylight as the irreplaceable input. On the axes that matter — spectrum, intensity, UV and near-infrared physiology — it literally is.

Use artificial light as a substitute, not a replacement.
• When you genuinely cannot get real light (winter, shift work, housebound), mimic the pattern of sunlight rather than chasing a magic bulb.
• A 10,000-lux light box meaningfully narrows the intensity gap and has clinical support for seasonal low mood (light_therapy_seasonal_and_beyond). It does not close the spectral or UV gap — useful, not equivalent.

Mimic the day/night contrast.
• By day: make indoor light as bright as practical. Brighter daytime light improves alertness; dim offices under-dose you.
• By night: go dim, warm, and low-blue in the hours before bed. Ordinary room light suppresses melatonin. The evening-blocking specifics (timing, glasses, screen settings) are owned by blue_light_blocking_evening; full darkness for the sleep period by darkness_and_sleep.

What to actually look for in lighting (without buying the hype):
• The highest-yield change is behavioural and free: more daytime outdoor light, dimmer warmer evenings. No purchase required.
• If you are buying bulbs anyway, tunable or warm-dimming options that let you go bright-cool by day and dim-warm by night serve the pattern — that is the real lever, not a "spectrum" marketing claim.
• You do not need a red-light panel, "circadian" smart bulbs, or blue-blocker glasses to get the core benefit. They are optional add-ons to a free behavioural pattern, sold as if they were the pattern itself.

Evidence detail

Why This Entry Exists

"Artificial light is poisoning you" is one of the fastest-growing wellness narratives, and like most fast-growing narratives it is half-true in a way that gets monetised. There genuinely is no consumer lamp that reproduces sunlight: the sun is fuller-spectrum, vastly more intense, and carries UV and near-infrared bands that no ordinary indoor light delivers. That part is real and worth stating plainly. But the same framing is then stretched into claims the evidence does not carry — that screen and LED blue light damages the retina, that indoor life is starving your mitochondria of "healing" near-infrared and making you sick — and those stretches are precisely what the red-light-panel, circadian-bulb, and blue-blocker industries are selling.

So this entry is the one-stop for the artificial-versus-natural question, built to be honest in both directions at once. It states the superiority of sunlight confidently where that superiority is measurable, and it refuses the disease-causation overclaim where it is not. The load-bearing claim — "substitute, not equal, so get real light and mimic its day/night pattern" — is Strong Evidence and survives regardless of how the speculative near-infrared-disease question eventually resolves.

What bad advice this protects against, in all directions:
• "Your indoor light is the same as being outside, just use a bright bulb" → false on spectrum and UV/near-infrared; you can buy back lux from a lamp but not the full solar spectrum, and you get none of the UV-mediated physiology.
• "Junk light is poisoning everyone — your screens are damaging your eyes and your LEDs are causing disease" → the retinal-damage claim is a debunked overclaim at real-world doses, and the near-infrared-deprivation-causes-disease thesis is an unproven hypothesis, both heavily amplified by people selling the fix.
• "Sunlight is superior, so maximise your UV exposure" → does not follow; the skin-mediated benefits sit alongside real skin-cancer risk, and the UV dose tradeoff is owned elsewhere, not a licence to bake.
• "It's all fine, nothing to worry about" → the conventional-lighting and device camp downplays the genuine circadian-disruption and flicker findings, which are real even though the doom version is not.

This entry owns the artificial-versus-natural comparison and the substitute-not-equal thesis. It does not re-argue evening blue-light blocking (blue_light_blocking_evening), the free morning-light habit (morning_sunlight_exposure), the broad circadian umbrella (circadian_rhythm_optimization), or UV and vitamin-D dosing (light_exposure_vitamin_d). It states those scope boundaries and defers the specifics.

Evidence

Organised by sub-area, with the tier signal inline. The headline is Strong, but the sub-areas split — read the tiers, not just the thesis.

Spectrum — the completeness gap (Strong Evidence for the physics; the harm inference is weaker).

1. Sunlight is roughly 3–5% UV, ~42% visible, and ~53% near-infrared at the surface — near-infrared is one of the two largest energy fractions, comparable to or exceeding visible depending on where the band is cut. Solar irradiance tables put a large share of the sun's surface energy in the infrared band (of zenith energy roughly 527W infrared, 445W visible, 32W UV), with peak spectral irradiance sitting around 882nm in the near-infrared. (Under some standard partitions, e.g. ASTM G173, visible edges ahead of near-infrared at ~53% vs ~43%; the ordering depends on the NIR/IR boundary, but either way near-infrared is a major fraction.) This is settled physics, not a contested claim. The point that matters: near-infrared is a large slice of sunlight, and it is the slice white LEDs almost entirely omit. (Solar-radiation physics references; ScienceDirect solar-spectra overview. Strong Evidence — settled physics, no commercial axis.)

2. White LEDs peak at ~450nm blue with a notch near 480nm, carry essentially no UV, and negligible near-infrared. Conventional white LEDs are a blue pump with a phosphor coat: a characteristic 450nm spike, a dip around 480nm (the "cyan gap," near the melanopic-sensitivity peak), and a spectrum that effectively stops in the visible. A sun-mimicking LED delivers more melanopic stimulus per lux than a standard 4000K LED (industry figures put it around 20% more), and daylight spans well beyond the LED's 350–650nm window. The spectral facts are Strong; the inference that this truncation harms you is Emerging at best. (SunLike-type chipmaker spectral comparisons — vendor-sourced, treat the magnitude as motivated; LED visual-performance literature. Spectral facts Strong; "truncated spectrum harms you" Emerging. BOTH-WAYS: the cyan-deficiency is directionally real but the figure comes from a company selling "natural spectrum" LEDs.)

Intensity — the brightness gap (Strong Evidence).

3. Outdoor daylight is 10,000–100,000 lux; typical indoor lighting is 100–500 lux — a 20-to-1000x under-dose. Bright day is around 10,000 lux, summer noon up to 100,000, overcast winter still 1,000–2,500. Typical home and office lighting at eye level is 100–500 lux. The circadian system is tuned to high daytime intensity, so ordinary indoor life chronically under-doses daytime light by one to three orders of magnitude. The clinical seasonal-affective benchmark of 10,000 lux for 30 minutes exists precisely because indoor light is too dim to entrain on its own. (Illuminance tables; clinical light-therapy standard. Strong Evidence — illuminance facts and "daytime brightness matters" are both well-established.)

Circadian and blue — the best-evidenced sub-area (Strong Evidence).

4. Evening room light (~200 lux) suppresses melatonin and shortens biological night by ~90 minutes. In a controlled in-patient study, exposure to ordinary room light (~200 lux) before bed, versus dim light (<3 lux), suppressed melatonin onset and shortened melatonin duration by around 90 minutes, driven by suppression more than phase-shift. Ordinary indoor evening lighting measurably disrupts the melatonin signal. (Gooley JJ et al., J Clin Endocrinol Metab 2011;96(3):E463–E472. Strong Evidence — landmark, replicated direction. Academic/NIH-affiliated, no industry conflict. Defer evening-blocking specifics to blue_light_blocking_evening.)

5. Brighter daytime light acutely improves alertness. At 1000 lux versus 200 lux (4000K), participants were less sleepy, more energetic, had faster psychomotor-vigilance reaction times, and higher physiological arousal. A Cochrane review of workplace lighting and daytime alertness (5 studies, 282 participants) supports the direction while flagging limited head-to-head illuminance trials. "Bright by day" is well-supported. (Smolders et al. 2012, Physiol Behav; Cochrane workplace-lighting review. Strong-to-Moderate — consistent acute effect; Cochrane is independent and flags the gap.)

Near-infrared and mitochondria — the SPLIT sub-area (mechanism Strong; indoor-deprivation Emerging-to-Experimental).

6. The photobiomodulation mechanism is real and characterised — at therapeutic doses. Red (~600–700nm) and near-infrared (~760–940nm) photons are absorbed by cytochrome c oxidase (Complex IV), dissociating inhibitory nitric oxide and raising mitochondrial membrane potential, oxygen consumption, and ATP, with the enzyme upregulated on repeated dosing. This is the genuine mechanism. It does not, by itself, establish that ambient indoor near-infrared deprivation matters. (Nature Sci Rep mechanism work; Frontiers Neurosci transcranial-PBM reviews. Strong-to-Moderate for the mechanism at therapeutic doses. Academic, but widely cited by panel marketers to imply consumer benefit the mechanism studies do not show.)

7. Clinical photobiomodulation evidence is use-specific and often low-certainty. Umbrella and systematic reviews report modest short-term benefit for some indications (tinnitus, some tissue and aesthetic uses) but "very low certainty" and explicit cautions against standalone use for others (e.g. knee osteoarthritis); deep-tissue benefit is unconvincing. Heterogeneous parameters undermine pooled conclusions. So even therapeutic near-infrared is Moderate for narrow uses, not a general health upgrade. (Umbrella review PMC12326686; LLLT review PMC11503318; tinnitus/SSNHL review PMC12681270. Moderate for validated narrow uses; Emerging for general "PBM optimises health." Mixed funding; the field has a positive-result incentive.)

8. "Indoor light deprives you of healing near-infrared and causes disease" is a hypothesis, not a finding. The subcellular-melatonin thesis proposes that near-infrared (the largest slice of sunlight) drives locally-consumed mitochondrial melatonin as an antioxidant, and that indoor life cuts the supply. It is mechanistically interesting and explicitly framed as hypothesis-generating; human disease-outcome data do not exist. This is the entry's most emotionally compelling and least-proven claim — wall it. (Zimmerman & Reiter, Melatonin Research 2019; Reiter et al., Biology/MDPI 2023, PMC9855654. Emerging-to-Experimental — hypothesis, not outcome-proven. BOTH-WAYS: the lead author has lighting/near-infrared commercial ties and the hypothesis underwrites "buy a panel" marketing. Do NOT present as established.)

Flicker — real for a minority (Moderate for the susceptible; Experimental as a universal claim).

9. LED/PWM flicker provokes headache and eye strain in a susceptible subgroup, not everyone. 100Hz fluorescent flicker (~35% modulation) roughly doubled headache incidence versus 32kHz in a double-blind study, concentrated in a small subgroup; migraineurs developed headaches from architectural flicker far more than controls (around 41% versus 8%). The effect is real and concentrated, not universal. Who is affected matters more than whether the effect exists. (Wilkins et al., temporal-light-modulation literature; migraine-flicker provocation studies. Moderate for the susceptible-minority effect; Experimental for "flicker harms everyone." Academic, but flicker-free-monitor vendors amplify it.)

Retinal harm — the DEBUNK (Strong Evidence against the overclaim).

10. Ordinary screen and LED blue light does NOT damage the retina or raise macular-degeneration risk at real-world exposures. The American Academy of Ophthalmology's position is that everyday screen and LED blue light does not damage the retina or increase age-related macular degeneration risk, and that blue-blocking lenses lack evidence for disease prevention or eye-strain reduction. Retinal-toxicity scare claims rely on extreme, direct, continuous lab irradiances unlike normal use; digital eye strain comes from reduced blinking and glare, not blue light per se. Note carefully: this debunks the retinal-damage claim, not the circadian one — evening blue still suppresses melatonin (different organ, different claim). (American Academy of Ophthalmology position; Ophthalmology & Therapy narrative review, Springer 2023. Strong Evidence — mainstream ophthalmology consensus debunking the overclaim. BOTH-WAYS: counters the blue-blocker industry; AAO is the independent professional body.)

UV, vitamin D, and nitric oxide — what no lamp does (Strong-to-Moderate).

11. UVA lowers blood pressure via skin nitric-oxide stores, independent of vitamin D. A single UVA dose (2 SED) to skin lowered blood pressure by mobilising cutaneous nitric-oxide stores, independent of vitamin D and of nitric-oxide synthase, with falling nitrate and rising nitrite. A cardiovascular effect no UV-free indoor light can deliver. (Liu D, Fernandez BO, Feelisch M et al., J Invest Dermatol 2014, PubMed 24445737; Weller/Feelisch, Karger. Moderate — mechanism plus human study, smallish n≈24, replication ongoing. Academic. Defer sun/vitamin-D dose tradeoffs to light_exposure_vitamin_d.)

12. UV triggers cutaneous beta-endorphin — a sunlight-specific effect that also tempers sun-maximalism. UV exposure drives skin beta-endorphin (POMC-derived), shown to mediate opioid-like reward and even UV-seeking behaviour in mice, with beta-endorphin induced in human skin in vivo. Another skin-mediated effect with no indoor-light analogue — and a built-in caution that sun-seeking has a real neurochemical pull, so "sunlight is superior" must not become "maximise UV." (Fell GL, Fisher DE et al., Cell 2014;157(7):1527–1534, PMC4117380. Moderate — strong mechanism, mouse behaviour plus human skin expression. Academic.)

13. The synthesis: even a clinical light box buys back lux but not spectrum. A 10,000-lux seasonal-affective light box narrows the intensity gap to sunlight but cannot close the spectral or UV/near-infrared gap — it is bright visible light only. That is the crisp operational basis for "substitute, not equal": you can purchase lux from a lamp; you cannot purchase the full solar spectrum or the UV-mediated physiology from a standard one. (Seasonal-affective light-therapy standard combined with the solar-spectrum and illuminance facts above. Strong Evidence — a logical synthesis of two well-established facts.)

Mechanism

Why the day/night pattern is the thing that matters. The circadian system reads light through melanopsin-containing retinal cells that are most sensitive to short-wavelength (blue-ish) light and tuned to intensity. High daytime light entrains and stabilises the clock and acutely lifts alertness; light at night does the opposite, suppressing melatonin and pushing the clock later. Indoor life inverts the natural contrast — too dim by day to entrain properly, too bright (and too blue) by night to let the night signal rise. The fix is not a special bulb; it is restoring the contrast: bright by day, dim and warm by night.

Why spectrum is not interchangeable with brightness. Lux measures visible brightness weighted to human vision. It says nothing about UV or near-infrared, which the eye cannot see but the skin and (per the contested hypothesis) the mitochondria respond to. A lamp can be matched to sunlight on lux and still deliver none of the UV-driven nitric-oxide and beta-endorphin physiology, and little to none of the near-infrared. This is why "just use a bright bulb" is a category error: brightness and spectrum are different axes, and only the sun maxes both.

Why the near-infrared mechanism is real but the indoor-deprivation leap is not. The photobiomodulation pathway — near-infrared photons absorbed by cytochrome c oxidase, displacing inhibitory nitric oxide, raising ATP — is genuine at therapeutic irradiances. The leap that fails is from "concentrated therapeutic doses do this in tissue" to "ambient indoor near-infrared deprivation causes disease." Those are different doses, different exposures, and different evidence bars. The mechanism being real is not evidence that your living room is harming you.

Why the retinal-damage fear is separable from the circadian truth. The retina is not meaningfully damaged by everyday screen or LED blue light because real-world irradiances are nowhere near the extreme lab doses used to show photochemical injury. That is a dose fact about the photoreceptors. It is fully compatible with evening blue light disrupting the clock via melanopsin at ordinary indoor brightness — a different cell population, a different endpoint. Holding both is not a contradiction; conflating them is the error in both directions.

Risks And Contraindications

• Tier-creep is the central hazard. The satisfying "fake light is making you sick" framing tempts borrowing the Strong circadian credibility to prop up the Emerging-to-Experimental disease-causation claims. Keep them firewalled: confident on circadian, intensity, spectral incompleteness, and UV-uniqueness; explicitly hedged on "indoor light is making you sick."
• The retinal debunk is not a blanket "blue light is harmless." Everyday blue light is harmless to the retina at normal doses; evening blue still suppresses melatonin (different organ, different claim). Do not let the debunk erase the genuine circadian point.
• "Sunlight is superior" is not a licence to maximise UV. The skin-mediated benefits sit alongside real skin-cancer risk, and UV carries a genuine neurochemical pull (the beta-endorphin "UV addiction" finding). Sun-maximalism is its own error; the dose tradeoff is owned by light_exposure_vitamin_d and sunscreen_mineral_vs_chemical_and_sensible_sun.
• Resist the pull toward a product recommendation. The honest conclusion — get real sun, mimic the day/night pattern indoors — requires buying nothing, which cuts against both seller camps. A panel, blue-blockers, or "circadian" bulbs are at best optional; treating them as the answer is the marketing talking.
• Flicker sensitivity is real for some, not all. People prone to migraine or who notice headache/eye strain under certain lighting may benefit from flicker-free fixtures; this is a targeted accommodation, not a universal mandate.

Controversy

Nature: a genuine physical truth (sunlight is spectrally and energetically superior) entangled with a wellness overclaim (artificial light is poisoning you) and a commercial counter-claim (it's all fine), with error at both poles. This is a both-ways one-stop precisely because both camps are partly right and partly selling something.

Position A — "Sunlight is superior and artificial light is making you sick." The wellness-market take.
• Best evidence: real and large where it stays grounded. Sunlight is fuller-spectrum, far brighter, and carries UV and near-infrared no consumer lamp matches; evening indoor light measurably suppresses melatonin; bright daytime light improves alertness. The substitute-not-equal core is well-supported.
• Where it's wrong: it overshoots into disease-causation. The retinal-damage claim is rejected by mainstream ophthalmology at real-world doses, and the near-infrared-deprivation-causes-disease thesis is an unproven hypothesis. It borrows Strong circadian credibility to sell Experimental conclusions.

Position B — "It's all fine, your screens and bulbs are harmless." The reassurance/industry take.
• Best evidence: correct on the specific overclaims — normal screen/LED blue light does not damage the retina, and blue-blockers lack disease-prevention evidence. The doom version is genuinely unsupported.
• Where it's wrong: it downplays the real findings — evening room light shortens biological night, daytime under-dosing dulls alertness, flicker harms a susceptible minority, and sunlight really does deliver UV-mediated physiology no lamp does. "Nothing to see here" is as much an overclaim as "junk light."

The funding/bias dimension — cui bono, both ways. The doom framing pays the red-light-panel makers (who need "indoor light lacks healing near-infrared" to sell panels, and whose foundational hypothesis has lighting-industry ties), the "human-centric / circadian lighting" makers (who profit from "your bulbs are circadian-wrong"), the blue-blocker sellers (who profit from a retinal fear the AAO rejects), and the wellness influencers monetising "junk light." The reassurance framing pays the conventional lighting, display, and device manufacturers, who downplay the genuine circadian and flicker findings. The honest read sits between them and benefits no seller.

Realised Position: Both sides are partly right, which is the whole point. Sunlight is the real thing and artificial light is a stand-in — useful and worth using well (bright by day, dim and warm by night), never confused for the original. We state the superiority confidently where it is real (spectrum, intensity, UV-mediated physiology) and refuse the disease-causation overclaim where it is not (retinal damage, "fake light is making everyone sick"). The actionable core — get real daylight when you can, mimic its day/night pattern when you can't — is robust no matter how the speculative near-infrared question resolves, and it costs nothing. That it sells no product is the tell that it is tracking truth rather than a SKU.

Cross-Pillar Connections

This is a genuinely cross-pillar topic — it spans circadian (sleep), nervous-system regulation (mental), and mitochondrial energetics (physical).
• Sleep (circadian_rhythm_optimization): the circadian umbrella this entry feeds; the day/night light pattern is the master input to the clock.
• Sleep (morning_sunlight_exposure): owns the free morning-light habit and its protocol; this entry explains why real light beats a bulb, then defers the how-to.
• Sleep (blue_light_blocking_evening): owns the evening melatonin-suppression and blue-blocking specifics; this entry holds the broader artificial-versus-natural comparison and points there for the evening protocol.
• Sleep (darkness_and_sleep): owns full darkness for the sleep period itself; the night end of the day/night contrast.
• Sleep (light_therapy_seasonal_and_beyond): owns clinical light-box use for seasonal low mood — the best-evidenced "substitute" application of artificial light.
• Cross-pillar (light_exposure_vitamin_d): owns UV dosing and the vitamin-D / sun-tradeoff story this entry deliberately does not re-argue.
• Mental (modern_lifestyle_sympathetic_load): the broader "modern environment is mismatched to our physiology" theme that the indoor-light story is one strand of.

What would change our mind

Falsifiability: explicit upgrade/downgrade criteria from source

• We'd upgrade the near-infrared-deprivation claim from Emerging-to-Experimental toward Moderate if a powered, randomised human trial showed that adding or removing ambient near-infrared changes a hard clinical outcome (glucose regulation, blood pressure, mitochondrial markers) at realistic environmental irradiances — not therapeutic-panel doses, and not authored by parties selling near-infrared hardware.
• We'd revisit the retinal-damage debunk if longitudinal cohort data linked chronic real-world LED/screen exposure to measurable macular or retinal change. No such data exist now, and the ophthalmology bodies would update first.
• We'd broaden the flicker concern beyond the susceptible minority if objective dose-response data showed harm in non-susceptible people at common PWM frequencies.
• We'd strengthen "sunlight superiority" further if the UVA-to-nitric-oxide blood-pressure and beta-endorphin findings replicate in larger trials with outcome (not just mechanism) endpoints.
• What would NOT move us: the substitute-not-equal core (settled physics plus illuminance facts), the priority of the day/night pattern (well-established circadian science), or the separation of the retinal-damage claim from the circadian claim (different organ, different dose). Across all of it, independent (non-seller) funding is the decisive variable.

Industry bias note

Structural incentives the evidence base may reflect

This is a topic with commercial pressure at both ends, which is why the physics and the independent professional-body consensus are the anchors.
• The "junk light" seller end: the red-light-therapy panel market (well into the hundreds of millions and growing) needs the "indoor light lacks healing near-infrared" premise, and the foundational near-infrared-deprivation hypothesis has lighting-industry ties. The "human-centric / circadian lighting" market (a multi-billion sector growing fast) profits from "your bulbs are circadian-wrong." Blue-blocker-glasses sellers profit from a retinal fear the AAO explicitly rejects. Wellness influencers monetise "junk light is poisoning you." All four benefit from the doom framing.
• The reassurance/incumbent end: conventional lighting, display, and device manufacturers profit from "it's all fine," and downplay the genuine circadian-disruption and flicker findings. The seasonal-affective-lamp industry markets the 10,000-lux figure while staying quiet about spectral incompleteness.
• The clean signal: the honest read benefits no seller. Sunlight really is spectrally, intensity-wise, and UV/near-infrared superior, and evening indoor light really does disrupt melatonin — so the doom camp has a kernel of truth. But the retinal-damage and near-infrared-disease claims are overclaims — so the reassurance camp is right on those specifics. Realised's non-commercial position, which sells nothing and recommends a free behavioural pattern, is the tell that it is tracking truth rather than a product.

Artificial Light vs Sunlight: A Substitute, Never an Equal