Chihuahua With Eye Patch. Perhaps if you stood directly in front of her, with her facing you at the same level, and zoomed in on her right eye, and took more pictures, it would show up better. Some chihuahuas have color combinations, which include:
Some blue merle chihuahuas exhibit heterochromia, meaning they may have one blue eye and one dark brown eye. Try it on your dog again. This means that the eyes nose and even the nails will be a light color.