Jesus showed how our bodies fill with light or with darkness,

“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. Therefore take heed that the light which is in you is not darkness” (Luke 11.34–35).

What do you put before your eyes? Whatever it is, that determines what fills your body.