I have been using the Kiehl's Multi-Corrective Eye-Opening Serum for about three weeks now, and because it has taken a while to form an opinion on the product I decided to do a first impressions review combined with my thoughts mid-way through the review month.

We received the eye serum in sachet samples, so I can't comment on the packaging of the original product. Five sachets needed to cover the 30 day review period, and I personally think of sachet samples as single-use because once opened it feels a bit unhygienic after a day or two.

This serum has a light fluid texture which absorbs very quickly and easily - perfect for those who don't like rich and creamy eye creams. It feels cooling and refreshing on application and does feel as though it 'wakes up' tired eyes.

After using it for three weeks I don't see a big difference to my eye area. I think it definitely does hydrate the area well and as a result it does smooth out fine lines. However, it doesn't plump up the eye area to the same extent that a more emollient eye cream would.

It is meant to be a 5-in-1 product which lifts and firms the eye area. Because I do not have crow's feet or loss of elasticity around my eyes I can't really see this effect. It hasn't had any effect on the dark shadows under the corners of my eyes. If it had faded under-eye shadows I would have given it 5 out of 5 for effectiveness. But I think for hydration and application it scores quite well.