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.
Arcana Coelestia #3820
3820. 'And Leah's eyes were weak' means that the affection for external truth is weak so far as the understanding of it is concerned. This is clear from the representation of 'Leah' as the affection for external truth, dealt with in 3793, and immediately above in 3819; from the meaning of 'the eyes' as the understanding, dealt with in 2701; and from the meaning of 'weak' as its being such in comparison with the affection for internal truth. The fact that affections for external truth are weak so far as the understanding of it is concerned, or what amounts to the same, so far as people governed by those affections are concerned, becomes clear from external - that is, general - ideas which have not yet been filled in with their particular details. They are feeble and shaky ideas, which so to speak allow themselves to be carried along by every puff of wind, that is, to be won over to every opinion. But when those same ideas have been filled in with their particular details they emerge as firm and steadfast ideas, for they then possess the essence and form meant by 'beautiful in form and beautiful in appearance' as Rachel was, who represents the affections for interior truth.
 Let the following example show what is meant by external truths and the affections for them, and what by internal truths and the affections for these, and the fact that the former are 'weak eyed' in comparison with the latter, which are 'beautiful in form and appearance': Those governed by external truths know no more than the general truth that good should be done to the poor. They do not know how to tell who are truly the poor, let alone know that in the Word the expression 'the poor' is used to mean those who are so spiritually. Consequently they do good to bad persons and to good ones alike, without realizing that doing good to bad people is doing bad to good, for the bad are then given the opportunity to do bad to those who are good. This is why people possessing this kind of simple zeal are infested so strongly by the crafty and deceitful. But those governed by internal truths know who the poor are, tell one poor person from another, and do good to each according to his individual character.
 Take another example. Those governed by external truths know no more than the general truth that the neighbour ought to be loved. They as a consequence believe that every individual is the neighbour in the same degree, and so every individual ought to be embraced with the same love. Believing this, they allow themselves to be misguided. Those however who are governed by internal truths know which degree of the neighbour each person belongs to and that any one person is the neighbour in a different degree from another. Consequently they are aware of countless things which those governed by external truths do not know. They do not therefore allow themselves to be led astray by the mere name of neighbour, or to do what is evil by performing that good which the name alone persuades them to do.
 Take yet another example. Those governed by external truths alone imagine that the learned will shine like stars in the next life, and that all who have worked in the Lord's vineyard will have a greater reward than others. But those governed by internal truths know the expressions 'learned', 'wise', and 'intelligent' are used to mean those in whom good is present, whether they possess any human wisdom and intelligence or not, and that it is these who will shine like stars. They also know that those who work in the vineyard receive a reward, each according to the affection for good and truth which motivated him in his work, and that those who work from selfish and worldly motives, that is, from self-aggrandizement and enrichment as motives, have their reward during their lifetime, but in the next life their lot is with the evil there, Matthew 7:22-23.
From these examples it is evident how weak in understanding those people are who are governed by external truths alone, and that internal truths are what give them essence and form, and also what determine the character of the good with them. Nevertheless people governed by external truths, and at the same time when in the world simple good was present in them, receive internal truths and resulting wisdom in the next life, for by virtue of that simple good they are in the right state and have the capacity to receive them.
(References: Genesis 29:17)