1.4 | Importance of Responses to Stimuli in Animals

Stereoscopic vision

• Both eyes located in front of the head.

• A narrow field of vision

• Fields of vision overlap to a great extent. Overlapping fields of vision produce vision in three dimensions

• Three dimensional images formed in the overlapping fields of vision allow the distance, size and depth of objects to be estimated accurately.

• The ability to estimate distance accurately helps animals to hunt.

• Humans and most predators have stereoscopic vision

Monocular vision

• Both eyes located at the sides of the head

• A wide field of vision

• Fields of vision do not overlap or overlap only slightly

• Two dimensional images formed in the non-overlapping fields of vision prevent the distance, size and depth of objects from being estimated accurately.

• A wide fi eld of vision helps animals to detect their enemies coming from any direction.

• Most prey have monocular vision.