Device for sampling tear fluid that comprises: an extraction element (202) adapted to be applied on the eye to draw tear fluid therefrom, comprising at least one tube (209) and a distal portion (201) with at least one opening (207), a collection vessel (203), connected to said tube (209), suction means (210) adapted to continuously draw tear fluid from the eye to the collection vessel (203), through the extraction element (202) for a period higher than 10 minutes once the extraction element (202) is in place.