Matt 6:22 “The lamp of the body is the eye. If therefore your eye is good, your whole body will be full of light.
It is important to know that the implication here is, also that not everything we see has a “good” effect. “If your eye is good” tells us that there is the possibility that what we see CAN fail to give us the “light” He is talking about. If the eye does not take in what is “around us” rightly (rooted in the content and teaching of the Word of God, based on the other passages in the NT) rightly, as “light” then our bodies will NOT be “full of light”. We certainly WANT the body to be “full of light” and thus, Solomon says, we ought to see to it that our eyes are looking and interpreting (via the Word of God and NOT our own preferences) what it is that we see so that it can be to us what God desires for it to be. Again this is NOT a matter of our preferences, but of God’s desire for us.
In Luke 11 Jesus gives us the Parable of “The Lighted Lamp”:
The lamp of the body is the eye. Therefore, when your eye is good, your whole body also is full of light. But when your eye is bad, your body also is full of darkness.