Assembly for storing and mixing two substances

A storage assembly for two substances to be mixed prior to use, comprising

• a closable dropper tip, a first storage chamber formed by the closable dropper tip and a first container part), the first container part being provided with at least one aperture a second storage chamber formed by a second container part, the second container part comprising an open end part, which second container part closes off the at least one aperture in a first operational position, wherein the first container part and second container part are moveable with respect to each other, and are in fluid communication with each other through the at least one aperture in a second operational position,
• wherein the total flow surface area of the at least one aperture is at least equal to a cross sectional area of the first container part wherein the first container part comprises a tubular part which is provided with the at least one aperture, and wherein in the second operational position, the first storage chamber and second storage chamber provide a single mixing chamber via the at least one aperture providing an internal volume with no flow resistance.