We can watch from both outside and the inside of a building through a window. The eyes of men are called 'the windows of the heart'. This is because things of heart are revealed through the eyes or things seen by eyes can be put in heart. If we see things that belong to goodness, such as truth and love, then goodness will be planted in the heart. However, if we see wicked and licentious things, evil will be piled up in heart (Luke 11:34-36). So, we should see only things of righteousness and goodness and put them in heart.