This highly effective combination of Caffeine and Hyaluronic Acid works to brighten, de-puff and replenish wrinkle-smoothing hydration to tired eyes. The cooling rollerball applicator allows the lightweight serum to glide gently onto delicate under-eye skin. Recommended for use morning and night. Remove cap and gently glide rollerball on undereye area starting from the inner corners moving outward. Allow serum to dry down before applying moisturizer or night cream. For those with sensitive skin, we advise testing a small amount on the neck to ensure no irritation before applying to face.