Think for a minute about all the images you see on a daily basis. They could be still images or moving images (video). It's estimated that the average person sees up to 10,000 ads a day, double the 2007 number and up to 20 times more than we saw in the 70's. And that's just ads, the images we usually try to ignore! Then there's social media pictures, and memes, and videos. We see images on TV and in newspapers and books. People show us images on their phones, and then there's all the images we intentionally seek out on the internet for better or worse.
Now think about Jesus' day. There were very few "images" to even see. Statues or paintings of various Roman gods perhaps, but no images that were exact representations of actual things. And yet Jesus says in Luke 11:34, "Your eye is the lamp of your body. When your eye is healthy, your whole body is full of light, but when it is bad, your body is full of darkness." Much evil starts with the eyes. David's adultery with Bathsheba and murder of her husband started with his eyes (2 Sam 11:2). What we see with our eyes can lead to jealousy, envy, and covetousness. In the garden of Eden, when Eve saw that the tree was good for food and Satan promised that their (spiritual) eyes would be opened, Adam and Eve ate the fruit.
Instead of subjecting our eyes to things that will lead us astray, we should focus our eyes (physical and spiritual) on the things of God. "I will not set before my eyes anything that is worthless" (Ps. 101:3). "I will meditate on your precepts and fix my eyes on your ways" (Ps 119:15) "The eyes of all look to you, and you give them their food in due season" (Ps. 145:15). Or as the writer the Hebrews says, "Let us fix our eyes on Jesus, the author and perfecter of our faith, who for the joy set before him endured the cross, scorning its shame, and sat down at the right hand of the throne of God" (Heb. 12:2). When the Hebrews grumbled against God in the desert and the Lord sent serpents to bite them, He offered salvation through Moses. Moses built a bronze serpent on a pole, "if a serpent bit anyone, he would look at the bronze serpent and live" (Num 21:9). So, we look to Jesus raised up on the cross and risen from the dead, so that we too might live.