5 ms·

Show HN: I built a daily sunlight tracker

46 points by vickipow 1y ago

I kept trying to explain how important outdoor light is and how most people aren’t getting enough. Eventually I figured that showing is more effective than telling. So we built a free app that uses your Apple Watch or iPhone to automatically track your light exposure throughout the day. It tells you if you’re getting enough, shows you how consistent you are, and rewards habits that support hormone balance. It's in beta on TestFlight, let me know what you think!

stek29 1y ago
Looks beautiful! Here are some thoughts: - Having a dark theme seems logical for an app focused circadian rhythms, would be nice to have a dark appearance - Not being able to switch between days by swiping felt quite annoying: the Home page requires two taps to change to another day, and the Progress page needs one — but it could’ve been a swipe. And the calendar on the Day page can’t be swiped down, only closed by tapping on the (x). I hadn’t even realized that Apple had rolled out Time in Daylight — Apple Health hasn’t promoted or highlighted it like it does for other new Categories, and even then, the visualization still feels lacking. I have been trying to get more consistent morning natural light exposure lately, so this is perfect timing!
- krtkush 1y ago
  > I hadn’t even realized that Apple had rolled out Time in Daylight Unfortunately, it is not the most accurate. If you wear full sleeved clothing which cover your Apple Watch, it will report wrong numbers.
  - vickipow 1y ago
    Yeah unfortunately you have to have the screen exposed for a few minutes each time you go outside. I spoke to the team at Apple, they said as long as you have a couple of minutes in the sunlight while you're on a walk it will then use sensor fusion to count the rest of the time outside.
- vickipow 1y ago
  Thanks so much! Appreciate the feedback. Will add those updates to our list of things to change (lots of improvements to make). Glad to hear you're getting more consistent morning light, it's imo one of the most powerful things you can do for your health.
Fraaaank 1y ago
>how most people aren’t getting enough What are you basing this on? What counts as 'enough'? And how are you tracking light exposure?
- snarf21 1y ago
  There are countless studies that billions of people are Vitamin D deficient. Our bodies are designed to get most of that from the sun. Lots of people never even leave their house on a given day. https://pmc.ncbi.nlm.nih.gov/articles/PMC3068797/ https://pmc.ncbi.nlm.nih.gov/articles/PMC3068797/
  - Fraaaank 1y ago
    I should've been more specific. The study you link states that 'To prevent vitamin D deficiency, one should spend 15 to 20 minutes daily in the sunshine with 40% of the skin surface exposed.'. The screenshot on lume health shows a goal of 120 minutes. Moreover, sun exposure is not by definition 'healthy'. Spending two hours in the sun at noon in the middle of summer does more harm than good.
    - agensaequivocum 1y ago
      > Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking. https://pubmed.ncbi.nlm.nih.gov/26992108/ https://pubmed.ncbi.nlm.nih.gov/26992108/
      - brokegrammer 1y ago
        The study seems to be incredibly flawed. > Women with active sun exposure habits were mainly at a lower risk of cardiovascular disease (CVD) and noncancer/non-CVD death Not surprised there because people who spend more time outdoors will typically be participating in physical activity at the same time, while people who avoid sun exposure will typically be seated while participating in sedentary activities. If we want to see if sun exposure is the sole reason for longevity, we will have to force the subjects to sit on a couch outside. Claiming that not getting sunlight is the same as smoking is pure garbage.
justmarc 1y ago
Nice! An Android version would also be appreciated :)
- vickipow 1y ago
  Working on it! Thanks for the feedback.
  - justmarc 1y ago
    Consider flutter, it may make your life a lot easier if you want to further develop this into something more substantial.
    - vickipow 1y ago
      Thanks! Will do
coolandsmartrr 1y ago
Looks cool! A couple questions: (1) Are you supposed to join the waitlist to use this ("Get Early Access"), or can you just start using via TestFlight ("Download Today")? I see two different links on this page. (2) How does this app measure the amount of light received by the Apple Watch? Does the Watch have such sensors and expose such APIs?
- vickipow 1y ago
  Thanks (1) You can join the waitlist for our hormone tracking device, the app is available for download today on TestFlight. Eventually the app will be used to show you the connection to your hormone balance (like cortisol etc.) and your light exposure. They are very tightly linked! (2) there is a light sensor in the display of the Apple Watch that automatically tracks it. It works ~80% of the time, but struggles if you have a big jacket
  - dylan604 1y ago
    Most people have their phone in a pocket or purse or similar while outdoors. Wouldn't this require the phone to be out and exposed to light in order to work correctly? So not only are you trying to get people to change habits of getting outside, you're also requiring they change habits with the devices as well. Good luck with that, and I mean that with more sincerity than snark but not no snark.
    - vickipow 1y ago
      The light sensor is in the Apple Watch display (behind the screen) it's what it uses to adjust the screen brightness. So if it's exposed to the sun it will count it automatically
achillesheels 1y ago
Pretty cool! I’m working in this space right now with architects and building owners. The science has advanced unto a certain knowing of melatonin secretion getting in the way of mental alertness under poor artificial illumination. Hit me up if you’re interested in learning more or how I can move your office space towards a renovation on the build owners dime: joseph@ledcompliant.con
- vickipow 1y ago
  Thanks! Reaching out.
metalman 1y ago
ummmmmm, if you dont have some kind of tan lines, you are not getting enough sunlight the app is pre loaded at birth .......though,I get it, as there is a significant demographic who will only trust there (beloved) device, and will benifit from the prompt, perhaps, perhaps not, as there is no possible way to break out all of the inumerable ways that human phisiology has adapted to ambient conditions on our planet, into seperate apps, so.....
- tolerance 1y ago
  I'm with metalman on this.
- vickipow 1y ago
  I get what you're saying. The product we're working on in the background is a wearable hormone monitor that actually shows you at the molecular level how much sunlight impacts your hormones - we've found this to be the most powerful lever for behavior change. But in the meantime, we have been using the saying "you can't improve what you can't measure" to help people get more sunlight.
shellwizard 1y ago
Why everything these days it's an app /rant
asdf6969 1y ago
Hormone optimization is just the newest way of calling someone the f slur since it’s not cool anymore.. f slur, soy, cuck, incel, now I also have to worry about how much sun I get if I want to avoid bullying. Give me a break

46 points by vickipow 1y ago

stek29 1y ago

Looks beautiful! Here are some thoughts: - Having a dark theme seems logical for an app focused circadian rhythms, would be nice to have a dark appearance - Not being able to switch between days by swiping felt quite annoying: the Home page requires two taps to change to another day, and the Progress page needs one — but it could’ve been a swipe. And the calendar on the Day page can’t be swiped down, only closed by tapping on the (x). I hadn’t even realized that Apple had rolled out Time in Daylight — Apple Health hasn’t promoted or highlighted it like it does for other new Categories, and even then, the visualization still feels lacking. I have been trying to get more consistent morning natural light exposure lately, so this is perfect timing!

krtkush 1y ago
> I hadn’t even realized that Apple had rolled out Time in Daylight Unfortunately, it is not the most accurate. If you wear full sleeved clothing which cover your Apple Watch, it will report wrong numbers.
- vickipow 1y ago
  Yeah unfortunately you have to have the screen exposed for a few minutes each time you go outside. I spoke to the team at Apple, they said as long as you have a couple of minutes in the sunlight while you're on a walk it will then use sensor fusion to count the rest of the time outside.
vickipow 1y ago
Thanks so much! Appreciate the feedback. Will add those updates to our list of things to change (lots of improvements to make). Glad to hear you're getting more consistent morning light, it's imo one of the most powerful things you can do for your health.

Fraaaank 1y ago

>how most people aren’t getting enough What are you basing this on? What counts as 'enough'? And how are you tracking light exposure?

snarf21 1y ago
There are countless studies that billions of people are Vitamin D deficient. Our bodies are designed to get most of that from the sun. Lots of people never even leave their house on a given day. https://pmc.ncbi.nlm.nih.gov/articles/PMC3068797/ https://pmc.ncbi.nlm.nih.gov/articles/PMC3068797/
- Fraaaank 1y ago
  I should've been more specific. The study you link states that 'To prevent vitamin D deficiency, one should spend 15 to 20 minutes daily in the sunshine with 40% of the skin surface exposed.'. The screenshot on lume health shows a goal of 120 minutes. Moreover, sun exposure is not by definition 'healthy'. Spending two hours in the sun at noon in the middle of summer does more harm than good.
  - agensaequivocum 1y ago
    > Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking. https://pubmed.ncbi.nlm.nih.gov/26992108/ https://pubmed.ncbi.nlm.nih.gov/26992108/
    - brokegrammer 1y ago
      The study seems to be incredibly flawed. > Women with active sun exposure habits were mainly at a lower risk of cardiovascular disease (CVD) and noncancer/non-CVD death Not surprised there because people who spend more time outdoors will typically be participating in physical activity at the same time, while people who avoid sun exposure will typically be seated while participating in sedentary activities. If we want to see if sun exposure is the sole reason for longevity, we will have to force the subjects to sit on a couch outside. Claiming that not getting sunlight is the same as smoking is pure garbage.

justmarc 1y ago

Nice! An Android version would also be appreciated :)

vickipow 1y ago
Working on it! Thanks for the feedback.
- justmarc 1y ago
  Consider flutter, it may make your life a lot easier if you want to further develop this into something more substantial.
  - vickipow 1y ago
    Thanks! Will do

coolandsmartrr 1y ago

Looks cool! A couple questions: (1) Are you supposed to join the waitlist to use this ("Get Early Access"), or can you just start using via TestFlight ("Download Today")? I see two different links on this page. (2) How does this app measure the amount of light received by the Apple Watch? Does the Watch have such sensors and expose such APIs?

vickipow 1y ago
Thanks (1) You can join the waitlist for our hormone tracking device, the app is available for download today on TestFlight. Eventually the app will be used to show you the connection to your hormone balance (like cortisol etc.) and your light exposure. They are very tightly linked! (2) there is a light sensor in the display of the Apple Watch that automatically tracks it. It works ~80% of the time, but struggles if you have a big jacket
- dylan604 1y ago
  Most people have their phone in a pocket or purse or similar while outdoors. Wouldn't this require the phone to be out and exposed to light in order to work correctly? So not only are you trying to get people to change habits of getting outside, you're also requiring they change habits with the devices as well. Good luck with that, and I mean that with more sincerity than snark but not no snark.
  - vickipow 1y ago
    The light sensor is in the Apple Watch display (behind the screen) it's what it uses to adjust the screen brightness. So if it's exposed to the sun it will count it automatically

achillesheels 1y ago

Pretty cool! I’m working in this space right now with architects and building owners. The science has advanced unto a certain knowing of melatonin secretion getting in the way of mental alertness under poor artificial illumination. Hit me up if you’re interested in learning more or how I can move your office space towards a renovation on the build owners dime: joseph@ledcompliant.con

vickipow 1y ago
Thanks! Reaching out.

metalman 1y ago

ummmmmm, if you dont have some kind of tan lines, you are not getting enough sunlight the app is pre loaded at birth .......though,I get it, as there is a significant demographic who will only trust there (beloved) device, and will benifit from the prompt, perhaps, perhaps not, as there is no possible way to break out all of the inumerable ways that human phisiology has adapted to ambient conditions on our planet, into seperate apps, so.....

tolerance 1y ago
I'm with metalman on this.
vickipow 1y ago
I get what you're saying. The product we're working on in the background is a wearable hormone monitor that actually shows you at the molecular level how much sunlight impacts your hormones - we've found this to be the most powerful lever for behavior change. But in the meantime, we have been using the saying "you can't improve what you can't measure" to help people get more sunlight.

shellwizard 1y ago

Why everything these days it's an app /rant

asdf6969 1y ago

Hormone optimization is just the newest way of calling someone the f slur since it’s not cool anymore.. f slur, soy, cuck, incel, now I also have to worry about how much sun I get if I want to avoid bullying. Give me a break