00:00I wake up in the morning and I want to reach for my phone,
00:07but I know that even if I were to crank up the brightness
00:09on that phone screen,
00:11it's not bright enough to trigger that cortisol spike
00:14and for me to be at my most alert
00:17and focused throughout the day
00:18and to optimize my sleep at night.
00:20So what I do is I get out of bed and I go outside,
00:24and if it's a bright, clear day
00:27and the sun is low in the sky
00:29or the sun is starting to get overhead,
00:31what we call low solar angle,
00:32then I know I'm getting outside at the right time.
00:35If there's cloud cover and I can't see the sun,
00:38I also know I'm doing a good thing
00:40because it turns out, especially on cloudy days,
00:42you want to get outside
00:43and get as much light energy or photons in your eyes.
00:46But let's say it's a very clear day
00:48and I can see where the sun is.
00:50I do not need to stare directly into the sun.
00:53If it's very low in the sky,
00:55I might do that
00:56because it's not going to be very painful to my eyes.
00:58However, if the sun is a little bit brighter
01:01and a little bit higher in the sky,
01:02sometimes it can be painful to look at.
01:04So the way to get this sunlight viewing early in the day
01:08is to look toward the sun.
01:10If it's too bright to look at directly,
01:13well then don't do that.
01:14You just look toward it, but not directly at it.
01:16It's absolutely fine to blink.
01:18In fact, I encourage you to blink
01:19whenever you feel the impulse to blink.
01:22Never look at any light, sunlight or otherwise,
01:24that's so bright that it's painful to look at
01:26because you can damage your eyes.
01:28But for this morning sunlight viewing,
01:30it's best to not wear sunglasses.
01:32That's right, to not wear sunglasses,
01:35at least for this morning sunlight viewing.
01:37It is absolutely fine to wear eyeglasses or contact lenses,
01:42so-called corrective lenses.
01:43In fact, those will serve you well in this practice
01:46or this tool because they will focus the light
01:48onto your neural retina
01:49and onto those melanopsin,
01:50intrinsically photosensitive ganglion cells.
01:52If your eyeglasses or contact lenses have UV protection,
01:56that's okay.
01:58There's so many different wavelengths
01:59of light coming from the sun
02:01and they are bright enough
02:02that they will trigger the mechanisms
02:03that you want triggered at this early time of day.
02:07So try and get outside,
02:09ideally within the first five minutes of waking,
02:11or maybe it's 15 minutes,
02:13but certainly within the first hour after waking.
02:15I want to share with you three critical things
02:17about this tool of morning sunlight viewing.
02:20First of all, this is not some woo biology thing.
02:23This is grounded in the core of our physiology.
02:26There are literally hundreds,
02:28if not thousands of quality peer-reviewed papers
02:30showing that light viewing early in the day
02:33is the most powerful stimulus
02:35for wakefulness throughout the day,
02:37and it has a powerful positive impact
02:39on your ability to fall and stay asleep at night.
02:41So this is really the foundational power tool
02:44for ensuring a great night's sleep,
02:47and for feeling more awake during the day.
02:49Second of all, if you wake up before the sun is out,
02:55you can and probably should flip on artificial lights
02:59in your internal home environment or apartment
03:01or wherever you happen to live,
03:02if your goal is to be awake, right?
03:04If you wake up at four in the morning
03:05and you need to be awake,
03:06well then turn on artificial lights.
03:09Once the sun is out, however, once the sun has risen,
03:13then you still want to get outside and view sunlight.
03:16Some of you will wake up before the sun comes out.
03:20And if you're asking whether or not turning on artificial
03:23lights can replace sunlight at those hours,
03:25unfortunately, the answer is no.
03:28Unless you have a very special light,
03:30we'll talk about what kind of light,
03:32the bright artificial lights in your home environment are not,
03:36I repeat, are not going to be sufficiently bright
03:38to turn on the cortisol mechanism
03:41and the other wake-up mechanisms
03:43that you need early in the day.
03:45The diabolical twist, however,
03:47is that those lights in your home or apartment
03:50or even on your phone are bright enough
03:53to disrupt your sleep if you look at them too late at night
03:56or in the middle of the night.
03:57So there's this asymmetry in our retinal,
04:00our eye biology and in our brain's biology,
04:03whereby early in the day, right around waking,
04:05you need a lot of light, a lot of photons,
04:07a lot of light energy,
04:09and artificial lights generally just won't accomplish
04:12what you need them to accomplish.
04:13But at night, even a little bit of artificial light
04:16can really mess up your so-called circadian,
04:19your 24-hour clocks
04:20and all these mechanisms that we're talking about.
04:22So if you wake up before the sun is out
04:24and it's still dark,
04:25please turn on as many bright artificial lights
04:28as you possibly can or need,
04:30but then get outside once the sun is out.
04:33On cloudy days, you especially need to get outside.
04:37I repeat, on cloudy days, overcast days,
04:39you especially need to get outside and get sunlight.
04:41You just need to get more of it.
04:43Now, how much light
04:44and how much light viewing do you need?
04:46This is going to vary depending on person and place,
04:49literally where you live on earth,
04:51whether or not there's a lot of tree cover,
04:53whether or not you're somebody who has sensitive eyes
04:55or less sensitive eyes,
04:56it's really impossible for me to give
04:58an absolute prescriptive,
04:59but we can give some general guidelines.
05:01In general, on a clear day,
05:03meaning no cloud cover or minimal cloud cover,
05:05you want to get this sunlight exposure to your eyes
05:09for about five minutes or so.
05:12Could be three minutes one day,
05:13could be seven minutes the next day,
05:15about five minutes.
05:17On a day where there's cloud cover,
05:19so the sun is just peeking through the clouds
05:21or it's more dense cloud cover,
05:23you want to get about 10 minutes of sunlight exposure
05:27to your eyes early in the day.
05:28And on days that are really densely overcast
05:30or maybe even a rainy,
05:32you're going to want to get as much as 20 or 30 minutes
05:35of sunlight exposure.
05:37Another key thing is do not forget about,
05:41just don't try and get this sunlight exposure
05:43through a windshield of a car or a window,
05:46whether or not it's tinted or otherwise,
05:48it takes far too long.
05:49It's simply not going to trigger the relevant mechanisms.
05:52You would be standing there all day,
05:54trying to get enough light into your eyes
05:55from the morning sunlight.
05:56And by then the sun will have already moved
05:59from low solar angle to overhead,
06:01and it simply won't work for all sorts of mechanisms
06:03related to your circadian rhythm functions.
06:05So just don't try and do it through a windshield,
06:07sunglasses or a window.
06:10It's just not going to work.
06:11Get outside.
06:12If the weather is really bad,
06:14or for whatever reason, safety reasons,
06:15you cannot get outside,
06:16well then I suppose try and get near a window.
06:18That would be the last, last resort,
06:20but you really want to get outside
06:22to get the sunlight exposure.
