The Neutrogena Healthy Lashes Lash Enhancer Serum is a popular choice among Amazon shoppers. This serum is formulated with a blend of peptides, vitamins, and botanical extracts that help to nourish and strengthen the lashes. It is easy to apply and can be used on both upper and lower lashes. Many users have reported noticeable improvement in the length and thickness of their lashes after using this serum consistently. The serum is also safe for contact lens wearers and is ophthalmologist-tested. If you're looking for an affordable and effective lash enhancer, the Neutrogena Healthy Lashes Lash Enhancer Serum is a great option.