Track your light intake to improve sleep
Light strongly shapes your sleep. Button V1 and the Track app give you actionable insights to make the most of natural light.
Works with iPhone · Ships worldwide
Feel the difference light makes
Small changes to your daily light add up to how you sleep, wake and feel.
The right light by day helps you fall asleep at night.
Bright mornings, alert afternoons.
See when evening light keeps you wired.
Like a fitness tracker, for light
Clip it on and live your day. LYS Track turns your light into a simple daily picture, and tells you what to change.
Install LYS Track on your own iPhone and pair it with your Button V1.
Your Button syncs to your phone, and LYS Track turns your light exposure into insights and feedback, so you can see how light shapes your day.
Think of it as a fitness tracker for light: explore your data and what it means for you.
Five questions about when you sleep, in LYS Track or here on the site. Your morning and evening light are then judged against your own sleep window.
Four steps from clip-on to a better-lit day
Nothing to configure. Clip it on, sync, and start seeing your light.
- 01
Clip it on
Wear the Button on your collar or jacket with the sensor facing out. It records your light all day.
- 02
Sync with LYS Track
Open LYS Track with Bluetooth on and the Button syncs. Once a day is enough.
- 03
See your day
See when you got bright light, when you did not, and how your evenings look.
- 04
Make small changes
A walk before lunch, dimmer lights after dinner. See what each change does to your day.
Two short videos cover unboxing and wearing
Unboxing your Button
What's in the box and how the charging dock fits together.
Wearing your Button
Collar or upper chest, near eye level, with the sensor facing outward and uncovered.
Bright days. Dark nights
Experts recommend bright light by day and dim light in the three hours before bed. Most of us get it the wrong way round. LYS shows you where you stand.¹
¹ Targets from the 2022 expert consensus: Brown et al., PLOS Biology. pubmed.ncbi.nlm.nih.gov/35298459
Backed by science. Used everywhere light matters
Used in published research since 2021, across universities, hospitals and care settings worldwide.
More daylight, better sleep
In published studies using LYS Buttons, people who got more morning and daytime light slept better, and where people spend the day shapes the light they get.
Higher Levels of Morning and Daytime Light Exposure Associated with Positive Sleep Indices in Professional Team Sport Athletes
Found that greater morning and daytime light exposure was associated with more favourable sleep measures in professional team-sport athletes. LYS Button worn to measure ambient light exposure.
Read the study →Spatiotemporal Light Exposure Modeling for Environmental Circadian Misalignment and Solar Jetlag
Developed a spatiotemporal approach for studying environmental light exposure, circadian misalignment and solar jetlag, using LYS Button to collect individual light-exposure data.
Read the study →The Relationship of Light Exposure to Sleep Outcomes Among Office Workers, Part 1: Working in the Office vs. at Home Pre/Post COVID-19
Compared everyday light exposure and sleep outcomes when office workers worked in the office versus at home, recording personal exposure with a LYS Button.
Read the study →Button V1 with LYS Track
One wearable light sensor, the LYS Track app on your iPhone, and the light you actually get, day by day. A one-time price, shipped worldwide.
Button V1, USB-C charging dock, USB-C cable
Typically within 7 working days
No subscription, app included
iPhone
24 months
Need more spectral channels or flicker detection? See Button PRO.
Light data with activity context
Everyday light data with movement context, in a compact, unobtrusive design.
- Light data
- Red, green, blue and near-infrared (RGB + NIR).
- Movement sensing
- A 3-axis accelerometer adds activity context to light measurements.
- Compact and unobtrusive
- A compact, unobtrusive design for everyday wear.
Specs, best for and apps
- Battery life
- 5 days
- Sampling interval
- Every 15 seconds; custom intervals by arrangement
- On-device storage
- At least 24 hours at the default interval
- Syncing
- Once a day at the default interval
LYS Collect: research data collection, no feedback to participants (iOS and Android)
LYS Data Portal: manage participants, monitor collection and export data
Questions before you buy
The short answers people ask us most.
What does Button V1 do?
Clip it on and live your day. Button V1 records the light that reaches you, and the LYS Track app shows how much daylight you really get, when you're getting too much light at night, and the small changes that can help you sleep better and feel more awake.
Which phones does it work with?
LYS Track for personal use works with iPhone. You pair it with your Button V1 and it syncs over Bluetooth.
How much light do I need?
Experts recommend at least 250 mEDI lux during the day, under 10 mEDI lux in the three hours before bed, and under 1 mEDI lux while you sleep (2022 expert consensus).
How long does the battery last?
About 5 days per charge, and Button V1 keeps recording while it charges.
How much does it cost?
Button V1 is £300, a one-time price. It ships worldwide.
Is LYS a medical device?
No. LYS products are not medical devices and are not intended to diagnose or treat any condition.
Start seeing your light today
Button V1 with LYS Track on your iPhone.
- ¹ Targets from the 2022 expert consensus: Brown et al., PLOS Biology. pubmed.ncbi.nlm.nih.gov/35298459