Church Fathers on John 1:5

Whereas that life is the light of men, but foolish hearts cannot receive that light, being so encumbered with sins that they cannot see it; for this cause lest any should think there is no light near them, because they cannot see it, he continues: And the light shines in darkness, and the darkness comprehended it not. For suppose a blind man standing in the sun, the sun is present to him, but he is absent from the sun. In like manner every fool is blind, and wisdom is present…

This kind of darkness however is not in men by nature, according to the text in the Ephesians, You were some time darkness, but now are you light in the Lord.

throughout the whole foregoing passage he, had been speaking of creation; then he mentions the spiritual; benefits which the Word brought w with it: and the life was the light of men. He said not, the light of Jews, but of all men without exception; for not the Jews only, but the Gentiles also have come to this knowledge. The Angels he omits, for he is speaking of human nature, to whom the Word came bringing glad tidings.