I used this for about three years in conjunction with a prism lens .  (One drop in the SOM eye twice a day.) This was pre-surgery, and after I'd decided that I wasn't willing to try any more neuro or anti depressant drugs off-label. Initially, I think it did settle the eye a little, and even a little was helpful.  I noticed that the tortion and angle of my diplopia during a really bad spell seemed less, and there wasn't as much tugging pain. It helped some with driving. It did seem to lose its effect after awhile, so eventually I discontinued it.  No side effects--very easy to use.  I normally have pretty low blood pressure, and this didn't lower it any further.