The present invention relates to a cosmetic active ingredient for improving the appearance of the skin beneath the eyes. More particularly, the present invention relates to a cosmetic active ingredient comprising an extract of the marine algae, Fucus vesiculosus. The present invention also relates to topical cosmetic compositions comprising as an active component an extract of the marine algae, Fucus vesiculosus, alone or in combination with additional cosmetic active ingredients, to reduce the appearance of dark circles in skin beneath the eye.