When I first read that Jesus said “the eye is the lamp of the body” he lost me right there. Since I’m scientifically trained I know the eye does not emit light like a lamp. Our eyes are more like windows, letting light in.
But Jesus was speaking metaphorically. He was talking about a heart attitude. In Matthew 6:22-23 the context was the competition in our hearts between God and money. How we view money reveals where our treasure is. The direct translation of his description of eyes would use the words “single” or “evil”. Some modern translations use words like “healthy” or “unhealthy” which does not do justice to the Greek. A single eye can be related to the beatitude in Matthew 5:8, namely that the pure in heart will see God. A love of money is idolatry which Jesus attributed to an evil eye which brings darkness. Something strange about this verse is that my spiritual eye lights up my body. I would have thought it was my soul that got light from my heart attitude. But I think Jesus wants us to appreciate the importance of our bodies. He is aware of the close connection our bodies have to our souls, especially in the area he was addressing, namely daily needs.
In Luke 11:34-36 the context was the attitude of the Jews to him. They refused to believe that he had been sent by God and accused him of driving out demons by Beelzebul, the prince of demons. They wanted a sign from heaven before they would believe in him. Jesus had very harsh words for them, saying that the people of Nineveh and the Queen of Sheba would accuse them of their unbelief on Judgement Day. The reason: Someone greater than Jonah or Solomon was there in their midst! In Matthew 15:14 he spoke about blind leaders with blind followers. He also linked the blindness of the Jewish leaders with their unwillingness to acknowledge that they were sinners (John 9:41).
In both of the above cases the eye is the faculty we use to make judgements. Jesus used eyes in his teaching on how we ought to judge others (Matthew 7:1-6). We tend to overlook our own faults but see them in other people. Psychologists call this projection and much has been written on the topic. See https://en.wikipedia.org/wiki/Psychological_projection. On a positive note, Paul prayed for the Ephesians "that the eyes of your heart may be enlightened in order that you may know the hope to which he has called you, the riches of his glorious inheritance in his holy people" (Ephesians 1:18).
