3550. 'I am Esau your firstborn' means that it believed itself to be natural good itself. This is clear from the representation of 'Esau' and from the meaning of 'firstborn' as good, and indeed natural good, represented by 'Esau'. For the truth which a person possesses prior to regeneration is believed by him to be good itself. People who have perception know that it is not good but truth appearing under the form of good; but those who do not have perception are not aware of any such difference, as will also be more evident from what follows below.

It's common to say “I see” when we understand something. And indeed, “seeing” in the Bible represents grasping and understanding spiritual things. So it makes sense that the eyes, which allow us to see, represent the intellect, which allows us to understand spiritual things. This can also be used in the negative, of course; the Bible speaks of people having eyes and refusing to see, and the Lord when He was in the world advised plucking out an offending eye. These represent a refusal to acknowledge truth, or being misled by falsity.