Domestic ferrets are just one breed, the colors are the type of ferrets. Within the genus Mustela, ferrets belong to the subgenus Putorius, from which there are only three extant species: M. putorius, the European polecat; M. eversmanni, the Siberian, or steppe polecat; and M. nigripes, the black-footed ferret.
Nearsightedness, also known as myopia, is a common type of refractive error where close objects appear clearly, but distant objects appear blurry. The cornea and lens bend (refract) incoming light rays so they focus in front of the retina.earsightedness, also known as myopia, is a common type of refractive error where close objects appear clearly, but distant objects appear blurry. The cornea and lens bend (refract) incoming light rays so they focus in front of the retina.
Farsightedness is a focusing problem usually resulting from an eye that is too short in relation to its focusing parts. Because of the reduced length, the muscles adjusting the lens may fatigue, or the lens may not be able to respond enough to focus the light rays. The retina thus receives a blurred image of light.