Our Origin Story
Like millions of people living in northern latitudes, our founders struggled with dark, brutal winters. Every year around November, the symptoms were predictable: hitting snooze four times, dragging through morning meetings, craving carbohydrates at 3 PM, and feeling an unshakeable cloud of low energy.
Eventually, we bought a popular "10,000 Lux" light therapy lamp from Amazon. We put it on our desks, turned it on for 20 minutes every morning, and waited for the magic to happen.
Nothing changed.
Frustrated, we borrowed an optical lux meter and measured the actual photon flux at our normal typing distance (about 24 inches away).
The meter didn't read 10,000 Lux. It read barely 1,200 Lux.
Because of the inverse-square law of optical physics, sitting 24 inches away from a compact tablet lamp meant we were receiving less than one-eighth of the clinical dose. To get the 10,000 Lux promised on the packaging, we would have had to lean our faces 7 inches from the plastic diffuser—an unnatural, uncomfortable posture that nobody can maintain while doing real work.
We realized that millions of people were throwing light therapy boxes into closets, assuming "phototherapy doesn't work for me," when in reality, they were simply victims of unmentioned distance drop-off.
That was the catalyst for KeepSunshine: building free, transparent digital calculators that do the real optical math for you, paired with honest, independent product breakdowns.
Our Core Values
🔬 Evidence First
Every calculator is calibrated against peer-reviewed chronobiology research—including the Terman clinical phototherapy protocol, Brown et al. (PLoS Biology 2022) melanopic lux models, and Mayo Clinic sleep guidelines.
🚫 Zero Marketing Fluff
We don't accept sponsored placements or paid product reviews. When a lamp is too small to reach 10,000 Lux at normal desk distance, we say so directly in our review.
🔓 100% Free & Private
All of our calculators are completely free to use, require zero account creation or logins, store zero personal data on servers, and work completely offline as an installable PWA.
⚖️ Transparent Monetization
We fund the hosting and maintenance of KeepSunshine exclusively through transparent Amazon Associates affiliate commissions when readers choose to buy recommended devices through our links, at no extra cost to them.
Editorial & Testing Standards
To ensure our content adheres to the highest standards of informational accuracy and E-E-A-T (Experience, Expertise, Authoritativeness, and Trustworthiness):
- Real Distance Benchmarks: In all buying guides, we state the exact physical distance (in inches and centimeters) at which a lamp delivers its rated lux, rather than repeating manufacturer marketing bullet points.
- Peer-Reviewed Literature: We link directly to primary scientific literature (including DOI links where available) so readers can independently verify the research.
- Medical Distinction: We strictly distinguish between mild sub-syndromal winter blues (which responds well to behavioral hygiene) and clinical Major Depressive Disorder with Seasonal Pattern (which requires professional medical oversight).
Get in Touch
We welcome feedback, suggestions for new circadian tools, and scientific corrections from researchers and clinicians.
Reach out to us anytime at: [email protected], or visit our dedicated Contact Page.