K9 Perception Umwelt Sight (Vision) Sound (Audition) Touch (Soma) Smell (Olfaction) Umwelt The subjective schema with the animal organizes its experience of the environment. Sight Color & Motion Sensitivity Dogs see color like a human That is, they are red-green color blind deuteranope. (this occurs in 4% of human males). The of the eye contains the light sensitive cells. It contains 2 types: retina - responsible for color vision & details (dogs only have 3% cones). - sensitive to light, contrast, & motion. Rods have 2 types rather than 3. Deuteranopes cone Because dogs have more than humans, they can see better in the dark & rods are more sensitive to motion. Detail or Acuity Dogs do not have a fovea (or area with 100% & this results in less of an cones) ability to see details. They do have a (20% cones). visual streak If normal human vision is 20/20, then that of the dog is about 20/75. This means that a dog must be 20' away from an object to clearly visualize it’s details, while a human with normal vision could clearly visualize the details from 75'. Thus, humans are more likely to see a stationary object in the distance (like a deer) than dogs. Vision - Dogs see better at night for 2 reasons: They have more rods. They have a (a surface behind the that reflects light tapetum lucidum retina back through it). BTW, the tapetum lucidum gives the dogs eyes their eerie shine at night. Depth & Field Due to the placement of the eyes, humans have an overlap of the field of each eye of 140o; dogs, less than 100o. This results in the dog having limited ability to (or focus on items at different distances). Thus, humans are better accommodate at depth perception. Dogs, however, have a wider overall field (about 250o vs. 180o in humans) & thus see more of the world. Comparisons
K9 Perception Umwelt Sight (Vision) Sound (Audition) Touch (Soma) Smell (Olfaction) Umwelt The subjective schema with the animal organizes its experience of the environment. Sight Color & Motion Sensitivity Dogs see color like a human deuteranope. That is, they are red-green color blind (this occurs in 4% of human males). The retina of the eye contains the light sensitive cells. It contains 2 types: - responsible for color vision & details (dogs only have 3% cones). Rods - sensitive to light, contrast, & motion. Deuteranopes have 2 cone types rather than 3. Because dogs have more rods than humans, they can see better in the dark & are more sensitive to motion. Detail or Acuity Dogs do not have a fovea (or area with 100% cones) & this results in less of an ability to see details. They do have a visual streak (20% cones). If normal human vision is 20/20, then that of the dog is about 20/75. This means that a dog must be 20' away from an object to clearly visualize it’s details, while a human with normal vision could clearly visualize the details from 75'. Thus, humans are more likely to see a stationary object in the distance (like a deer) than dogs. Vision - Dogs see better at night for 2 reasons: They have more rods. They have a tapetum lucidum (a surface behind the retina that reflects light back through it). BTW, the tapetum lucidum gives the dogs eyes their eerie shine at night. Depth & Field Due to the placement of the eyes, humans have an overlap of the field of each eye of 140o; dogs, less than 100o. This results in the dog having limited ability to accommodate (or focus on items at different distances). Thus, humans are better at depth perception. Dogs, however, have a wider overall field (about 250o vs. 180o in humans) & thus see more of the world. Comparisons