Double Vision

Naturally, from birth onward, we have been habituated to make sense of our world through the five senses.  The understanding (heart) becomes molded from those experiences.  For instance, we will naturally gravitate toward things or activities that have been pleasurable to our senses in the past, and distance ourselves from those that were not.  Our understanding groups good experiences in one category and bad ones in another. Every decision that is made, is based or built upon these experiences.  My chain-reference Bible labels it as your “earthly vision”.  
There are however, many things that initially appear good to the natural eye, yet when pursued, the end of them is spiritual destruction and even death.  
 
There is a way that appears to be right, but in the end it leads to death. (Prov.14:12 NIV)

Because God is omniscient (he knows the begging to the end), he has given us his word to help guide and maneuver us through life. Not to withhold anything from us as many may think, but to do us good.  The more time that is spent in the word, the more you begin to see the world through the lens of scripture. Scripture begins to mold your understanding (heart), and you are able to see things for what they truly are.  You are given a different set of eyes in a sense, commonly referred to as “spiritual vision”.  

So, you can ignore God’s word, walking through life according to your senses (earthly vision) and thus deal with the destructive consequences.  The Bible also refers to this as walking in the flesh. 

Or, you can listen to the word, and live according to Biblical truth (spiritual vision).  Also known as walking in the spirit. 

…lean not unto thine own understanding.  In all thy ways acknowledge him…(Pr. 3:5-6 KJV) 

There are numerous examples in scripture, where individuals followed their senses (earthly vision) and later dealt with the consequences…
 

Eve
When the woman saw that the fruit of the tree was good for food and pleasing to the eye, and also desirable…, she took some and ate it. (Gen 3:6 NIV)
 

Lot
And Lot lifted up his eyes, and beheld all the plain of Jordan, that it was well watered every where, before the LORD destroyed Sodom and Gomorrah…(Gen 13:10)
 
 
Achan
I saw in the plunder a beautiful robe from Babylonia, two hundred shekels of silver and a bar of gold weighing fifty shekels, I coveted them and took them. (Jos. 7:21)
 

You see at one point we all lived according to the flesh (earthly vision), Paul in Ephesians 2…

All of us also lived among them at one time, fulfilling the cravings of our flesh and indulging its desires... (vs. 3)
 
But God has given us a better way of living, again to do us good and not harm.  This does however involve a restraining of the senses on our part.  Biblically described as dying to self.  You do this by simply choosing to obey the word, rather than “gratifying the desires of the flesh”.  
Job clearly understood this concept of living according to the spirit, rather than obeying the desires of the flesh.  In his appeal to God he stated…

Let me be weighed in an even balance, that God may know mine integrity.  If my steps have turned from the path, if my heart has followed my eyes, or if impurity has stuck to my hands…(Job 31:7 BSB)

When Jesus was tempted of the devil in the wilderness, he also was presented the decision of gratifying the flesh or choosing to obey Gods word …

Again, the devil took him to a very high mountain and showed him all the kingdoms of the world and their splendor…Away from me, Satan! For it is written: ‘Worship the Lord your God, and serve him only.  (Matt. 4:10 NIV)
 
He chose rather to obey the word.  Later in Matthew chapter 6:22  Jesus teaches 
The light of the body is the eye: if therefore thine eye be single, thy whole body shall be full of light. (KJV)
 
You see, there is a constant battle between the two, in a way, we have “double vision”.  When we dye to self, that is restrain the senses, we choose not to live according to the flesh (earthly vision) but rather to the spirit (spiritual vision).  It is an easy win for the spirit, and our eye is now “single”.  
 
 
Supporting text

If your right eye causes you to sin, gouge it out and throw it away. It is better for you to lose one part of your body than for your whole body to be thrown into hell. (Matt. 5:29 BSB)