Question

Answer 10.11.12please

9 Draw a top-down version of a horse's head (or deer). It does not have to be accurate as long as it has a long snout and the eyes on the sides of its head. Now draw lines out from its eyes demonstrating its visual fields based on eye placement 10 From your results from questions 8 and 9, briefly describe the difference in the visual fields of a primate versus a horse or a deer. 11 Discuss with your lab partnerfs), then provide a reason why that difference may exist and what it may relate to in the species' natural habitat. 12 Does having good depth perception mean we sacrifice another aspect of our vision? If so, what might that be? 8 An important primate feature is forward-facing eyes, which allows for depth perception. Close one eye, and then close the other eye before answering the following questions. Draw a person's head from the top/superior view (it could be just a simple circle), and fill in the location of the eyes. a b Based on your range of vision after closing each eye, in your sketch draw lines from the eyes that show the ap- proximate fields of vision for each eye (you will have two lines going out from each eye). Shade in the area of overlap between the fields of vision. This is how depth perception is accomplished-from overlapping visual fields. c

Answer 1

10- Visual perception in animals depends on the structure and adaptations of the eye that provides the initial evidence of potential visual capabilities within any species.

The position of the equine eye and resultant visual field varies greatly with that in primates . Visual capabilities of the horse are broadly inferior in particular, in acuity, accommodation, and color vision.

In primates, the frontally placed eyes convey a number of advantages where each eye has a visual field of approximately  with a large degree of binocular overlap. The consequence of receiving similar visual information from two eyes simultaneously is to increase visual acuity and to provide information about the distance and solidity of objects .Also means, that visual attention will be focused on stimuli that are positioned directly ahead.

Primates also have large eyes ; this feature ensures that a large image is formed on the retina allowing higher depth in vision.

In horses, the lateral position of the eye provides with almost panoramic vision,

The equine eye is large and prominent, located within enclosed orbits positioned laterally in the skull . Together with the size and curvature of the cornea, size and horizontal shape of the pupil, and angular extent of the retina, this provides the horse with extensive monocular vision.

In particular, from an anatomical perspective, a marked forward prolongation of the nasal retina provides the horse with a wide visual field . However, binocular overlap of the visual field is located down the nose of the horse . In addition, two blind spots have been identified within the equine visual field, one in front of the forehead and one directly behind the horse. But this is overcome by  the length and mobility of the neck, that allows  horses to bring such areas into view quickly.

So, with the head lowered, the horse has the benefit of being able to scan the lateral horizon with its monocular fields, while assessing the ground surface for both suitable food and safe footing with its binocular field .

11- In horses, visual system displays adaptations to particular environmental conditions, accentuating those features that are most important for the survival of this herbivorous prey species.

As horses spend majority of time grazing with their heads lowered and their eyes near ground level leaving vulnerable to predation. Although feeding activity in the horse has been found to occur throughout the day and night, this activity peaks after dawn and before dusk . Therefore , requires a visual system that is sensitive in low light levels (scotopic conditions), provides early warning of approaching predators, and can assess the immediate ground conditions quickly for a speedy escape. Panoramic vision, facilitates maximum detection of predators at the expense of the advantages of binocular overlap.

Horses are very sensitive to motion, as motion is usually the first alert that a predator is approaching. Such motion is usually first detected in their periphery, where they have poor visual acuity, and horses will usually act defensive and run if something suddenly moves into their peripheral field of vision.

In primates, as mentioned above, binocular vision  has been suggested that has an adaptive value, because enables prehension and  the ability to judge distances and grasp objects when moving between branches.

12- Depth perception is the ability to see in three dimensions and judge the distance of an object. It is also known as stereopsis. Binocular vision can perceive the depth and distance of objects.

But having depth perception diminishes our visual field. Since the eyes are both located in front, binocular vision can also see in front and from the peripheral view but not beyond these two.So the disadvantage is that we have narrow visual fields