The eyeglass coatings are not the same thing you find on watches. In fact they're very different. The ophthalmologic coatings (for eyeglasses) are applied using different technology and at much lower temps. As a result, they do not inhibit reflections to nearly the same degree nor do they hold up against scratching as well.
I once thought eyeglass coatings would suffice as well, but once I came to understand the technical details behind AR that changed. The industries served by the AR I'm using do not include eyeglass lenses. And there really isn't a possibility for there to be a crossover because the extreme heat in the AR chamber that is necessary for the durability of the coating would simply melt polycarbonate eyeglass lenses anyhow.