By narrowing or widening automatically in bright or dim light the lens behind the pupil gathers light, so a small picture of the object is formed. This image falls on the "film". Of course there is no film in the back of your eye. The picture is formed on the retina, which is like a screen lined with light-sensitive nerve cells. These cells send messages to the brain and you see as a result. The eye is a wonderfully created organ, but it sees nothing. The actual seeing occurs in the brain!
The Bible says, "Eye has not seen, nor ear heard, neither has entered into the heart of man, the things which God has prepared for them that love Him. But God has revealed them unto us by His Spirit" (1 Corinthians 2:9-10).
God has a wonderful plan and a wonderful home called heaven for those who are His children. But there are people who will never see it or know it. The Bible says that they are blinded by their unbelief. They are separated from God. Their sins have come between them and God, hiding His face so they cannot see and know Him.
The Lord Jesus said, "Except a man be born again, he cannot see the kingdom of God... Except a man be born of water and the spirit, he cannot enter into the kingdom of God" (John 3:3,5)
How can a person be made to see and understand the things of God? He must put his whole trust in the crucified, risen Son of God. Christ died for our sins according to the Scriptures. He was buried and He arose again the third day according to the Scriptures (See 1 Corinthians 15:3-4). By grace are you saved through faith (Ephesians 2:8). Jesus said, "I am the light of the world. He that follows Me shall not walk in darkness" (John 8:12). "I am the way..." (John 14:6). We are children of God by faith in Christ Jesus (Galatians 3:26) and our spiritual eyes are opened.
How well do you see?