These properties are necessary for the third advantage. It allows the angles of the eyes' lines of sight, relative to each other ( vergence), and those lines relative to a particular object ( gaze angle) to be determined from the images in the two eyes.This also allows a creature to break the camouflage of another creature. It can give stereopsis in which binocular disparity (or parallax) provided by the two eyes' different positions on the head gives precise depth perception.For example, humans have a maximum horizontal field of view of approximately 190 degrees with two eyes, approximately 120 degrees of which makes up the binocular field of view (seen by both eyes) flanked by two uniocular fields (seen by only one eye) of approximately 40 degrees. It gives a creature a 'spare eye' in case one is damaged.Neurological researcher Manfred Fahle has stated six specific advantages of having two eyes rather than just one: Binocular vision does not typically refer to vision where an animal has eyes on opposite sides of its head and shares no field of view between them, like in some animals. In biology, binocular vision is a type of vision in which an animal has two eyes capable of facing the same direction to perceive a single three-dimensional image of its surroundings. Type of vision with two eyes facing the same direction Principle of binocular vision with horopter shown

Prey eyes vs predator eyes