The effect of an antioxidant - rich diet on vision was compared making use of mice prone to having damage of the retina in old age in a very similar way as humans do. (ahealthblog.com)
But the biggest factor appears to be the increasing use of mice and rats in biomedical research. (sciencemag.org)
Still, preparing this post had to be done in stages because use of the mouse and keyboard is painful. (oldthingsnewblog.com)