Close your right eye and mentally note your field of vision with only the left one. Now try the same by closing your left eye. Okay now stop closing your eyes and appreciate the full field of vision available to you on account of your TWO EYES!This is one of the main advantages of us having two eyes. We have twice as much vision, so to speak. For an average well functioning pair of eyes, this binocular vision has a field of around 170o.The problem of parallax error in vision is reduced a lot because of this double eye vision. It also enhances our depth perception giving us a very good evolutionary advantage. Also, our ability to detect faint objects is more distinct. Thanks to our ‘two’ eyes, humans are able to enjoy stereoscopic vision. Some animals with two eyes like rabbits and buffaloes have 360o degree field of vision but they do not have stereoscopic vision. This is an advantage only available to animals with two eyes in the front of their head like us humans.
Because with one eye we will not able to see clearly, with the help of two eyes we are able to see corner view.
Ek kharab ho jaye to dusra kaam aayega .Hahahahahahahahah. Sorry I. Am joking

It gives a wider field of view .a human being has a horizontal fields of view of about150 with one eye and about180 with two eye.example of pencil , we can\’t meet the nips of pencil with one eye.
The problem of parallax error in vision is reduced a lot because of this double eye vision. It also enhances our depth perception giving us a very good evolutionary advantage.Our ability to detect faint objects is more distinct.Humans are able to enjoy stereoscopic vision. Some animals with two eyes like rabbits and buffaloes have 360 degree field of vision but they do not have stereoscopic vision. This is an advantage only available to animals with two eyes in the front of their head like us humans.