MN 137 discusses the six sense fields.
How can we understand lay equanimity with respect to the six sense fields?
For sights, lay equanimity arises for an uneducated ordinary layperson but such equanimity does not transcend the sight, and that's why it's called lay equanimity - says the sutta.
What does that mean? What is an example of lay equanimity?
And in this context what are the six kinds of lay equanimity? When seeing a sight with the eye, equanimity arises for the uneducated ordinary person—a foolish ordinary person who has not overcome their limitations and the results of deeds, and is blind to the drawbacks. Such equanimity does not transcend the sight. That’s why it’s called lay equanimity. When hearing a sound with the ear … When smelling an odor with the nose … When tasting a flavor with the tongue … When feeling a touch with the body … When knowing a thought with the mind, equanimity arises for the uneducated ordinary person—a foolish ordinary person who has not overcome their limitations and the results of deeds, and is blind to the drawbacks. Such equanimity does not transcend the thought. That’s why it’s called lay equanimity. These are the six kinds of lay equanimity.
MN 137