How good is a Tibetan Mastiff’s eyesight?

The Tibetan Mastiff’s eyesight is actually fairly good. Although it can only distinguish blue and yellow and is born nearsighted, its field of view is much wider than a human’s and it can see movement to the side and behind. In addition, its retina has many rod cells and a large cornea that lets in more light, so in very dim light it sees better than humans. Finally, newborn mastiffs have not yet opened their eyes, and for the first weeks their eyes are underdeveloped, so vision is poorer; once the eyes fully mature, vision reaches normal levels..