Luke 11:34

ὁ λύχνος τοῦ σώματός ἐστιν ὁ ὁφθαλμός σου. ‘Thine eye is the lamp of the body,’ since the word is the same as in the last verse.

ὅταν ὁ ὀφθαλμός σου ἁπλοῦς ᾖ. The eye in this clause is the ‘inward eye’ of conscience; the ‘illuminated eye of the heart,’ Ephesians 1:17-18. “Single,” i.e. unsophisticated; in its normal condition.

ἐπὰν δὲ πονηρὸς ᾖ. The ‘evil eye’ is especially one of hate, Romans 12:8; Sir 14:8-10. The inward eye should be spiritual; when it becomes carnal the man can no longer see that which is only spiritually discerned, and he takes God’s wisdom for foolishness, 1 Corinthians 2:14; 1 Corinthians 3:18-20.