Hi: This is heart breaking indeed. So, the bad news is that cataracts have begun to form, especially in one eye. The good news is that your horse still has sight out of one good eye and some sight out of the eye with the cataract. Research on Can-C reports that application of the Can-C eye drops as directed results in about 95% improvement in the subjects that were studied. Subjects have been dogs and humans – not horses – but researchers concluded that the Can-C helps reverse cataracts in all mammals including horses in, again, 95% of the cases. So, it is certainly worth a try, especially to insure that the good eye remains clear of a cataract.