Dog eyes and ears

The performance of the ear is highly developed. It can perceive higher frequencies than that of humans, ideally:
Man ~ 20-20,000 Hz, maximum sensitivity in the range from 2000 to 4000 Hz
Dog ~ 15-50.000 Hz (according to other sources to 100,000 Hz), maximum sensitivity at 8000 Hz.
The moving of the dog’s ears make him locate noise sources better in three dimensions than a man could do, they are next to hearing as an important “signal” for optical communications.

Visual sense
Eye of a dog

Earlier, man proceeded from the assumption that dogs could only see shades of gray, black and white. According to current knowledge, dogs can see colors, but are red and green blind.   The eye of the dog has, like all mammals, two different photoreceptors, the rods are responsible for the vision of gray levels and the others studs are for the vision of colors. The rods are much more numerous and more sensitive to light than cones.

The cones provide color vision, but only with adequate lighting. This also applies to people.   In the twilight we see only in shades of gray. In dogs (as with most other mammals, but not in humans), the back of the eye “mirror” (this layer is called the tapetum lucidum), reflects from the back of the eye.  Dogs can therefore see at twilight a lot better than people.

The cones are specialized in a certain spectral range.  In humans there are three different receptors for the colors red, green and blue, from its three color signals in the brain. The dog has only two different types of cones that are sensitive to green and blue. Only part of the human color spectrum is covered.  Red is a color that the dog does not recognize. The color vision of dogs is slightly shifted towards tultraviolet and ends with the missing red receptor in yellow.

Vision and high color sensitivity in humans and dogs
There are other major differences.  In a dog’s eye, the blue area is the most sensitive. In the human eye in the green / yellow, 550 nm optimized visual acuity is probably lower, and on movement, stationary objects are suppressed by the brain.

The reason may lie in the fact that the motion of the prey of the wolf, is visually selected for it.  The field of vision of the dog is much larger than that of humans, it is about 240 degrees as opposed to 200 degrees in humans. The area can be seen in the three dimensions of the dog that is slightly smaller at around 90° than that of men (120 °).