An eye mask built around wild Siberian blueberry, from Natura Siberica's Antiox line.
Why wild northern berries, specifically
This is genuinely interesting, and it is not marketing.
Plants produce polyphenols — anthocyanins among them — partly as a defence: against ultraviolet light, against cold, and against the oxidative stress both cause. A plant under more stress makes more of them.
Wild berries growing at high latitude live under exactly that pressure: intense summer light for weeks on end, extreme cold, and a very short growing season. Studies comparing wild northern berries with cultivated ones consistently find higher polyphenol concentrations in the wild, cold-climate fruit — the small, dark, intensely flavoured berries are chemically more concentrated because they had to be.
The same principle explains why wild bilberries are darker all the way through than cultivated blueberries, which are pale inside: the pigment is throughout the flesh rather than just in the skin.
What an eye mask can and cannot do
Worth being straight about. Applied to skin, antioxidants have modest and gradual effects, over weeks rather than minutes, and the eye area is the hardest place to change because much of what shows there is anatomy rather than skin quality — a deep tear trough casts a shadow no product reaches.
What a good eye mask does reliably is hydrate. The skin around the eye is the thinnest on the face with the fewest oil glands, so it dries out first and shows it soonest; hydrated skin is plumper, and plumper skin creases less. That change is immediate, visible and temporary.
Applying it
Less than you think, further out than you think. Use the ring finger — the weakest, so it presses least — and tap rather than rub. Apply along the orbital bone, not against the lash line: warmth and blinking carry product inward on their own, and applying too close is what makes eyes sting and lids puff.
Note
External use only. Avoid direct contact with the eye. Patch test first if your skin is reactive.