In a real human eye, accommodation is accomplished by muscles that change the curvature of the crystalline lens. When an eye changes accommodation from a distant object to a near object, does the curvature of the crystalline lens increase or decrease?

The curvature of the crystalline lens increase

Explanation:

Since accommodation is the ability of the eye lens to change in shape so as to focus on an object. So, when we look at a far-away object, the ciliary muscles relaxes and moves away from the lens making the suspensory ligaments tight, pulling the lens, and causing its crystalline curvature to become thinner (decrease), so that light rays passing through it are bent less enabling them to focus on the retina.

However, the reverse happens when the human eye focus is switched to a near object, such that: ciliary muscles contracts, suspensory ligaments slackens, and crystalline lens becomes more curved (increase)

Thus, the change in accommodation makes the curvature of the crystalline lens to increase