An improved punctum plug is more easily visualized when positioned within a punctual canal of a recipient. The body of the plug features an outwardly exposed surface when properly positioned, and a substance causing at least the outwardly exposed surface to contrast with surrounding tissue, such that the use of the substance causes the plug to be more easily visualized than if the substance were not present. The substance, which may be disposed on the outwardly exposed surface or within the body of the plug, may include a saturated coloration, or may be phosphorescent, fluorescent or otherwise operative to reflect or re-radiate light to assist in
visualization. For example, the substance may include an organic or inorganic
phosphor or fluorescent material, reflective beads,
quantum dots, a dye or
pigment. Such reflection or re-
radiation may occur at the same or different
wavelength(s) compared to the illumination
wavelength(s), whether or not either or both are within the visible part of the spectrum. If outside the visible region, a
detector may be employed according to the invention for detecting the radiated light. A
system for determining whether or not a punctum plug is positioned within the punctal canal of a person's eye is also enclosed, including at least one optical element permitting the eye to view itself, to be viewed by the other eye, or by a second person.