In this episode of the Monday Masterclass, Dr. Leland Stillman and co‑host Amy explore whether wearing contact lenses affects the body’s circadian rhythm. They begin by framing the broader importance of light entering the eye for hormone regulation, noting that indoor environments filter out 98‑99% of UV light, creating a UV‑deficient setting with health consequences. The conversation then shifts to the specific question of how contact lenses interact with light: Amy reports a literature search that found limited research on the topic, so she investigates which wavelengths pass through common lenses. She highlights that many lenses, such as Acuvue, are marketed as UV‑blocking, primarily attenuating UVA and UVB rays, and discusses how this filtering might influence melatonin production and circadian timing. Throughout, the hosts reference scientific literature, Substack archives, and product specifications, while also considering practical consumer implications for morning and all‑day wear. The episode blends a brief overview of circadian biology with a focused examination of contact‑lens optics and their potential hormonal impact.
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It just like spins for a second.
Hello everyone. Dr. Leland Stillman and Amy are here today for another Monday Masterclass. Hello, Amy.
Hello. Hi.
How are you? How's the left coast?
Wonderful.
It is.
It's nice and sunny. It's warm. Probably not as warm as you guys, but it's still warm.
It's sweltering here.
Yeah.
We love it.
All right.
Where are we starting?
Okay. So we are gonna do a little bit of, um, going into contacts today. So someone had asked, um, you know, does it matter if you wear your contacts to get your circadian rhythm right? And so kind of like in the morning, um, wearing contacts, and then also throughout the day, is that going to mess up your circadian rhythm if you're wearing contacts? And so I will pull up my Share my screen. Okay, so let me get this over here. Give me one second, organize my screen here.
So for those of you who don't know If you get deep into the light literature and the effects of light on the brain through the eye, you start to ask questions like, well, what effect do contact lenses have on our brains, our minds, our hormones, our neurotransmitters, all the rest of it? And that is when you get into things like this question, right?
Mm-hmm.
And then sometimes little things, seemingly inconsequential things, will have a huge impact. Like, for example, for people who don't know, the glass that our sunlight comes through filters out all the UV light.
Yes.
99 or 98% of it. And that essentially means we live in a totally UV-deficient indoor environment, and that has real health implications, right? And then the question is, well, what do we do about it? Because most of you are in some way tied to some kind of indoor job or lifestyle or whatever.
So That's great. And then do you want to just go over real quick why we're even talking about circadian rhythms in general? I know most of your audience probably is well aware of it, but just like, um, just like a brief overview.
Light is important. For those of you who don't know why, look it up in the Substack archives and you will find out why.
Anyway, yeah, great. So as expected, we do not find a ton of literature on kind of the impact of contacts on our circadian rhythm. Or like the impact of, you know, does light actually get through them? And so I had to do a little bit of digging here and trying to figure out, okay, you know, which wavelengths of light actually come through contacts? What is influencing our melatonin production and our circadian rhythm? And so one of the things that I was looking at was the different types of rays that come through our contacts. And so one of the things that I found that contacts actually block is they mainly focus on blocking UVA and UVB rays. And so I found that, I guess I'll go to the first one. Actually, I'll go to, this was interesting. So first on the Acuvue, so this is a very common brand of contact lenses. And so just even going on their website, they say UV blocking in every Acuvue contact lens. And then—
This is really interesting.
Yes, I know. And this is what they're advertising.
It's very important. I really want to help you all as consumers become smarter consumers because people make big mistakes because of how their brains are wired. So go up all the way back up to the top real quick. So number 1, they, they're leading off
