I agree with @Thermion in regard to 'the most important part' or one might say in the context of sight - the 'sighting eye'. One's leading eye is the one that focuses on the perceived object. The other eye is off-centre. (If I point at something, then close each eye in turn, only one eye is 'sighting' directly on the object.)
Nature, our created nature, has instincts - instincts of flesh and blood. Instincts of self-preservation ; and not just instincts to preserve myself but a very strong instinct to preserve the human race - which will not be preserved more than about fifty years if we do not continue to reproduce.
But to allow oneself to 'focus' upon this, as the most important aspect of one's existence, is out of balance. Or to become subject to human emotions, affections, passions and instincts to an inordinate degree is downright wrong.
And if one is enslaved to such instincts to the degree where it is causing one to behave unsociably, inhumanly and ungodly : then, yes, better gouge the offensive member out of one's body and preserve one's spirit, in the hope of a better resurrection.
I have no right to 'separate' a woman in my heart from her family or from her husband, the deeper meaning to the word μοιχεύω (moi, chorizo), translated 'adultery' who has not (from the bosom of her family and from her own volition) been given to me.
It is unrighteous, it is inappropriate, it is disorderly and it is rude. It is unsociable, it is inhuman and it is ungodly.
God's purpose in creating male and female was to set forth, in nature, a demonstration of Christ and the Church, of faithfulness, loyalty, nurture, kindness and trust.
This is to 'see aright'.
They that are in the flesh cannot please God, as scripture says. It is they who are led of the Spirit of God that are not condemned :
There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit. [Romans 8:1 KJV]
But the law, and the knowledge of good and evil (as Eden testifies) will not help us who are created human. It is a way of death.
And Paul discovered no problem with nine commandments, only the tenth revealed sin within him - Thou shalt not desire. (See the whole of Romans chapter 7.)
Then, and only then, did he discover that there was a rule within him that was far, far stronger than the Law outside of him. When I would do good, evil is present with me. The good that I would, I do not ; the evil that I would not, that I do.
Oh wretched man ! he cries out from within himself. And kicks against the goadings of his own conscience.
Paul discovered that, within, in his own spirit, he desperately needed a Saviour and a real, effectual salvation, from the sin that dwelt deeply within his own nature.
'I am crucified with Christ' he was - eventually - able to say.
And such an experience, the spiritual apprehension of his own union with Christ in Christ's death - this, yes this, gave him liberty, gave him holiness and broke the bands of law/sin/guilt/failure - law/sin/guilt/failure that made his life unbearable.
And even then there are times . . . . .
Truly God is good to Israel, even to such as are of a clean heart. But as for me, my feet were almost gone; my steps had well nigh slipped. For I was envious . . . .[Psalm 73:1-3]
And the remedy ?
Until I went into the sanctuary of God ... Nevertheless I am continually with thee: thou hast holden me by my right hand. ... Whom have I in heaven but thee? and there is none upon earth that I desire beside thee ... My flesh and my heart faileth: but God is the strength of my heart, and my portion for ever. [Psalm 73 selections KJV]
To dwell in the sanctuary, to be in union with the Lord, to see the end of all flesh in the death of Christ - this is to see aright.
And if my sighting eye sees otherwise, then better to wrench it from me and enter into Life halt and limping and half-blind.
Better by far.