The concept of seeing with the heart is an established principle in Islam.
“It is not their eyes that are blind, but their hearts.”
It’s also acknowledged in Western culture.
“You only see clearly with your heart. The most important things are invisible to the eyes.”
The Little Prince, Chapter 21
Before we go further, we need to establish what it means to see with the heart, and what it does not mean.
The idea of seeing with the heart correlates to the modern psychological concept of intuition.
It does not refer to feelings. Feelings are emotions, while intuitions are perceptions.
Just like normal perception (that of the five senses) which functions in the present moment, intuitions also function in the here and now.
You cannot have an intuition about something that happened in the past or will happen in the future. Any feeling you have about those things is more likely to be an emotion than a perception.
The dichotomy between inward and outward sight can lead to overwhelming arguments between people. While everyone has access to intuitive perception, most refuse to use it. (The reverse is not true, for an intuitive person does not have the option to disregard their outward sight.)
The best analogy is that of autostereograms (“Magic Eye pictures”). Anyone can see the surface-level image. They can see the richness of the colours. The can appreciate the beauty of the pattern, and the intricacy of its detail.
But they cannot see the deeper image. They only see the surface.
Some people can see the hidden picture.
And they probably seem quite mad to the people who can’t.