"But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins" (2 Peter 1:3-15).
To lack the building blocks of spiritual character brings a steady deterioration of spiritual faculties. Two are mentioned in verse 9, namely, sight and memory. Spiritual blindness promotes spiritual forgetfulness. Without a doubt, seeing makes the biggest Impression. As Job confessed, "I have heard of thee by the hearing of the ear but now mine eye meth thee" (Job 42:5).
We see best when the contrast ratio is set right. When colors are similar, contrast diminishes. When they are opposite, contrast is brilliant. However, even he best contrast picture is wasted on a blind man. A sinful world is always in stark contrast to God's Holy Word, except to the spiritually blind.
Peter also warns of increasing myopic vision. He "cannot see afar off." He cannot focus on the distant future to see the consequences of his sin. And he cannot see his past any better, forgetting that sins once removed should not be repeated.
Thankfully, God's light can heal our eyes. "...in thy light shall we see light" (Psalm 36:9).