The lens is a transparent, disk-shaped structure in the eye that focuses light onto the retina, allowing us to see clearly. It is located directly behind the pupil and is held in place by fine ligaments (tough bands of tissue).
A dislocated lens is a lens that has moved out of position because some or all of the supporting ligaments have broken. Some people are born with conditions that can cause weak ligaments and are prone to having a dislocated lens. For example, about half of all people with the hereditary disorder called Marfan's syndrome develop dislocated lenses. A dislocated lens also can be the result of trauma, such as being hit in the eye with a ball or fist. If all of the ligaments have broken so that the lens is loose within the eye, the lens is considered completely detached. If only some of the ligaments have broken, the lens may be pulled off center and is considered partially detached.