screen-filters
f.lux
f.lux is the original pioneer of circadian-aware screen filtering. It automatically adjusts your screen's color temperature based on your local sunrise and sunset, reducing blue light exposure as you approach bedtime.
Quality & Materials
Lightweight software that adjusts the color gamut of the display. It uses your location to sync with the solar cycle.
Evidence & Testing
f.lux has been cited and used in numerous academic studies regarding screen light and sleep quality.
Brand Transparency
While not open-source, the creators provide a wealth of research links and spectral maps on their website to explain the 'why' behind their presets.
Value Assessment
Unbeatable value as the software is free for personal use while providing professional-level circadian regulation.
Why Not Alternatives?
It is completely free and has been the gold standard for over a decade. While it lacks the PWM controls of Iris, its ease of use and 'set it and forget it' nature make it the best entry point for circadian health.
Sources & References
More in Circadian & Light
Ra Optics
Sunset Lenses (Clyde Frame)
Ra Optics is the industry leader in precision optics for circadian health, utilizing proprietary pigments that provide a sharp 550nm cutoff. Unlike most competitors, they use high-quality CR-39 plastic lenses which offer superior optical clarity compared to cheap polycarbonate.
Bon Charge
Sleep Blue Light Blocking Glasses
Bon Charge (formerly BluBlox) offers laboratory-tested lenses that block 100% of the blue and green light spectrum from 400nm to 550nm. Their frames are exceptionally high quality, and they offer prescription, reading, and non-prescription options.
BlockBlueLight
NightLens Blue Light Blocking Glasses
BlockBlueLight offers the best balance of clinical-grade spectrum accuracy and affordability. Their NightLens is specifically designed to block 100% of blue and green light up to 550nm, backed by accessible spectral analysis reports.
Swanwick
Classic Night Swannies
Swanwick is the brand that popularized blue blockers for sleep. Their orange 'Swannies' are effective at blocking blue light and are a reliable, well-reviewed entry point for those new to circadian optimization.