What is neomycin and polymyxin b sulfates and bacitracin zinc ophthalmic ointment and can it be used on a horse?

Neomycin, Polymyxin b sulfates, and bacitracin zinc ophthalmic ointments are typically sold as 'triple antibiotics' they each treat bacterial infections and work in conjuncture with each other to kill bacterial infections.

Yes they can be used on horses, you can get name brand or generic products that contain all three (hence the 'triple antibiotic' label). However you should consult your equine veterinarian before using any medication on or near a horses eyes.