1. The eyes can deceive us. Iago is suggesting that our eyes can fool us, leading us to believe things that are not true. For example, we might see someone who appears to be kind and trustworthy, but who is actually a villain.
2. The eyes are the most important sense. Iago is also suggesting that the eyes are the most important and valuable of all the senses. They allow us to see the world around us and experience all of its beauty and wonder. Without our eyes, we would be severely limited in our ability to understand and interact with the world.