Light within the 460–480 nm range is the primary band regulating our circadian rhythm: it boosts alertness during the daytime, yet strongly suppresses melatonin after dark. Wavelengths from 480–570 nm also produce secondary circadian effects, with human sensitivity gradually decreasing as wavelength increases. A subset of people with photophobia experience discomfort specifically to the 480–520 nm band — FL41 lenses are formulated for this group.
No single lens performs optimally for both day and night.
Our daytime clip-ons (FL41B / clear) filter excess harsh glare and unwanted screen blue light, while preserving the beneficial circadian signals your body needs. Our amber and red night clip-ons block these disruptive bands to support your natural sleep cycle; the red variant delivers stronger full-spectrum cutoff for highly sensitive users.
Everyone’s light sensitivity and needs are different. Please choose the combo that works best for you
