I read Luke 24:14-32 last night. Jesus walked with two of His own followers, people who had spent time with Him, and yet they did not recognize Him. But as we read the dialogue, we see that their minds were on carnal things. They were reasoning within themselves. They were focused on the geopolitical, on their idea that Christ would rescue Israel from Rome. Their eyes could not see Him because they were not discerning Him in the Spirit.
I think this parallels the passage in John 1. It says that no one has seen the Father at any time, but that the Son has REVEALED Him. Before the time of Christ, men saw only a dim figure of who God really was. But Jesus revealed to us the very image of the Father. We see, we perceive who God is through Christ. I don't think that this passage is talking about the literal eyes and the physical eyesight. The word used is that Jesus declared God. The word does not mean to see with the physical eyes, but rather to unfold who the Father really is. It is like me saying, "No one has really seen ME yet. They don't really know who I am. I want to explain to them who I really am."
Think of it this way. God is Spirit, and they that worship Him must do so in Spirit and in truth. It is only the Son that had a physical body. When Moses and Isaiah saw God, they were not really seeing God Himself. They were seeing some physical representation that God had, if this does not sound too strange, manufactured in order for them to see something, some representation of Himself. But they did not really SEE God. To see God, we must have Spiritual eyes.
So I think that really is the key to understanding why these verses sound contradictory. These verses are not talking, in my opinion, about literal, physical sight, but rather about revelation or spiritual sight.