Thimerosol as a *topical* antiseptic is rather different than an INJECTED preservative. In my particular case, I'm highly allergic to the stuff; it used to be used as a preservative in contact lens solutions and when I became sensitive to it I was then no longer able to use contact lenses. (my current eye infection feels very much like what it felt like to have that reaction, except it won't go away just because I stop putting something in my eye.