naphazoline

This is a vasoconstrictor found in many over-the-counter eye drops such as Naphcon-A and Opcon-A. By constricting the blood vessels on the conjunctiva surface, this makes the eyes look whiter.  Unfortunately, many people develop a rebound redness and their eyes actually look more red and swollen when the drop wears off. We see a similar response with Visine … which is why most eye doctors don’t recommend using vasoconstrictors.