A.T. Robertson Commentary 1 John 2:11

"But he that hateth his brother is in the darkness, and walketh in the darkness, and knoweth not whither he goeth, because the darkness hath blinded his eyes." — 1 John 2:11 (ASV)

Blinded (ετυφλωσεν). First aorist active indicative of τυφλοω, the very verb and form used in 2 Corinthians 4:4 of the god of this age to keep men from beholding the illumination of the gospel of the glory of Christ who is the image of God. The first part of the verse repeats verse 9, but adds this vivid touch of the blinding power of darkness. In the Mammoth Cave of Kentucky the fish in Echo River have eye-sockets, but no eyes.