We read in Matthew 6:22, “The light of the body is the eye: if therefore thine eye be single, thy whole body shall be full of light.”
Although Jesus spoke these words long before science and medicine had advanced to a point where much was known about the function and physiology of the human eye, the scriptures are in perfect accord with the considered opinions of modern specialists today. In fact, a noted oculist once had this to say in regard to this very Scripture:
“The seeing power of the body requires two eyes, each receives its own impressions, slightly different from that of the other, but apprehended by the brain as one impression. Select an individual object to look at. With the right eye you see the center and a little of the right side of the model, and vice versa with the left. by combining the two images, the brain has a comprehensive idea of the total object. The perception may then be said to be ‘single’ and, therefore, in regard to that object, the whole body is ‘full of light,’ but if the two eyes look in different directions, two separate images are carried to the brain. There is no true impression. The person having this double impression cannot regard and follow both images without getting into great confusion.”
Jesus made a spiritual application of this physical truth by pointing out that “no man can serve two masters.” A Christian needs an “undivided heart” (Ephesians 6:5-7; Colossians 3:22-24), if his eyes is to be “single’ to God’s glory!