Here "heart" is a metonym for a person's mind. The phrase "eyes of your heart" is a metaphor for one's ability to gain understanding. Alternate translation: "that you may gain understanding and be enlightened" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-metaphor]])
This may be stated in the active tense. Alternate translation: that God may enlighten your heart" or "that God may enlighten your understanding" (See: [[rc://en/ta/man/translate/figs-activepassive]])
What God has promised and will provide is spoken of as though it were property or wealth that one would inherit from a family member. Alternate translation: "the riches of all the glorious things he has promised to give to all God's holy people" (See: [[rc://en/ta/man/translate/figs-metaphor]])