SleepBlocks below 516 nm

Swanwick

Relax

Website · from $130Amazon

The verdict

A light evening lens. It blocks 72% of body-clock light, but 32 lenses block more, and under a warm 2700K bulb about 38% still gets through.

It will not protect melatonin at night. Think of it as a screen-comfort lens for the daytime.

Measured Sep 9, 2026 · 350 to 950 nm · how I test

Sleep strength

Partial

72% melanopic blocked

#33 of 61 lenses

Clarity

Light tint

79% of visible light passes

#21 of 61 lenses

Tint

Deep yellow

Blocks below 516 nm

Colors shift slightly warm

Red + near-IR

Passes

92% of 600 to 950 nm

Long wavelengths get through

Under your lights

Pick a light to see what the lens lets through.

79%of visible light gets through, cutting in at 516 nm
400 nm500 nm600 nm700 nm800 nm900 nmUVNear-infrared
What gets through the lens

How the world looks through it

Drag the handle. Left of the line is through the lens.

A woman draws colorful digital art on a graphics tablet at a wooden desk in a bright, modern office with bookshelves and other people working in the background.With lensWithout
WithoutWith lens
White page
Skin
Sky
Phone screen
Leaves
Red
Wood
Night sky

Simulated from the lens's measured color. A lens that blocks blue and green darkens cool colors and keeps warm ones.

Where it ranks

All 61 lenses. Up blocks more body-clock light, right is clearer. The best tradeoffs sit on the green line. Tap any dot.

99.7%99%95%90%50%0%0%20%40%60%80%100%Clarity (VLT) →Melanopic blocked →This lens

Selected

Swanwick Relax

72% blocked · 79% clarity · $130

Beat it on both

No lens I have tested blocks more and is clearer. This one sits on the best-tradeoff line.

Swanwick sells this lens in

Standard framesFits over glassesClip-onKids sizesMagnetic clip-onAdjustable nose padsSpring hingesPrescriptionAcetateMetal alloyAnti-reflectiveShips worldwide