“The eyes of your understanding being enlightened; that ye may know what is the hope of his calling, and what the riches of the glory of his inheritance in the saints, and what is the exceeding greatness of his power to usward who believe, according to the working of his mighty power” (Ephesians 1:18-19).
The phrase “the eyes of your understanding” refers to the eyes of your heart or mind; and not the eyes of your spirit because your spirit is illuminated by the Spirit of God.
Your mind is the part of you that needs the illumination of the Spirit.
Give yourself entirely to the word so that you can be illuminated by the word to know what has been made available to you and walk in it.
You are in the light; allow the word to give light to your mind.