Sufism

The heart has an eye that sees what the physical eye cannot

Beyond the mirror image, al-Ghazali claims the heart possesses its own faculty of perception, distinct from the five physical senses, capable of directly registering realities that sight and hearing cannot reach.

Where Book 21 of the Ihya uses the mirror image to describe the heart's need for cleaning, al-Ghazali also develops a second, complementary image: the heart possesses its own eye, an inner faculty of perception he calls basira, insight, distinct from and ranked higher than the five physical senses. Through this inner eye a person can become directly aware of realities simply outside the range of sight or hearing, such as the actual state of one's own soul, the presence of God, or unseen influences on one's own actions, the way physical eyesight perceives color and shape. He treats this as a real epistemological claim rather than poetic exaggeration: the heart is a knowing organ in its own right, and its perceptions can, when unclouded, be more reliable than the physical senses about certain matters. He also notes this inner eye is more easily disrupted by sin and distraction than physical sight is by darkness.

Ihya Ulum al-Din