Fifteen years ago, most of us still lived under incandescent bulbs that naturally warmed up at night. Today, nearly all indoor lighting comes from blue-pump LEDs, and a growing debate is unfolding about whether those lights are quietly working against your body's internal clock.
Lighting Industry Report Downplays Circadian Health Concerns
The Illuminating Engineering Society, known as the IES, published a recommended practice document under the ANSI framework titled 'Supporting the Physiological and Behavioral Effects of Lighting in Interior Daytime Environments' (ANSI/IES RP-46-25). The report landed in February 2026 and immediately drew fire from circadian health researchers.
On page 18, section 5.1.1 carries a telling heading: 'Mistaken Use of Circadian in the Physiological Effects Lexicon.' That framing alone signals where the IES stands on the topic. The organization states that it is typical for sighted individuals to stay entrained to a 24-hour cycle even under poor lighting conditions, such as dimly lit offices and spaces with degraded lighting systems. It goes further, claiming there is no evidence of generally occurring non-entrainment among people living or working in environments with poor lighting.
Who Funds the Standards, and Why That Matters
The IES is not an independent research institution. It is funded by the lighting industry through memberships, subscriptions, trade shows, and publications. That funding structure matters because the standards the IES sets directly shape what products manufacturers need to build and sell.
Dr. Martin Moore-Ede, a circadian health researcher who has been vocal on the topic, argues that this financial relationship explains why the report reads the way it does. He sees ANSI/IES RP-46-25 as a deliberate effort to minimize the need for circadian lighting in commercial and residential spaces. The practical effect is straightforward: if the industry's own standards body says current lighting is good enough, there is little pressure on manufacturers to change what they produce.
The Blue Light Problem With Your Everyday LEDs
Most indoor lighting today is delivered by blue-pump LEDs. The core issue, according to Moore-Ede, is that this technology delivers too little 480 nm circadian blue during the day and excessive blue content after sunset. That is essentially the opposite of what your body needs.
Circadian lighting, by contrast, provides 480 nm blue-rich light during the day and blue-depleted light at night. The idea is to mirror the natural light cycle of the sun: bright and blue-shifted during daylight hours, warm and dim as evening approaches. Blue-pump LEDs do not do that. They give you the wrong signal at the wrong time, and the IES report essentially says that does not matter.
What This Means for You at Home
So why should you care about an industry standards document? Because these reports shape what ends up on store shelves. If the IES says circadian lighting is unnecessary, manufacturers keep making the same blue-pump LEDs, and those are the bulbs you find at your local hardware store.
The gap between what circadian science suggests and what the lighting industry standards endorse is real. Moore-Ede's critique highlights a tension that most consumers never see: the people writing the rules about lighting quality are the same ones selling the products. If you care about sleep quality, daytime alertness, or long-term health, it is worth understanding that the lighting in your home may not be designed with your biology in mind.
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