Lens Dislocation
Overview
Plain-Language Overview
Lens dislocation occurs when the clear lens inside the eye moves out of its normal position. This condition affects the eye's focusing system, which is crucial for clear vision. The lens is normally held in place by tiny fibers called zonules, and when these fibers weaken or break, the lens can shift. This can cause blurred vision, double vision, or even eye pain. It may happen due to injury, genetic conditions, or other eye diseases. Because the lens helps focus light onto the retina, its displacement can significantly impact how well a person sees. Early detection is important to prevent further vision problems.
Clinical Definition
Lens dislocation (ectopia lentis) is the displacement of the crystalline lens from its normal anatomical position due to disruption or weakness of the zonular fibers. It can be caused by trauma, inherited connective tissue disorders such as Marfan syndrome (due to mutations in FBN1), or metabolic diseases like homocystinuria. The condition leads to impaired visual acuity and may cause secondary complications such as glaucoma or retinal detachment. Clinically, patients present with symptoms of blurred vision, monocular diplopia, or astigmatism. The direction of lens displacement (superotemporal in Marfan syndrome, inferonasal in homocystinuria) can aid in differential diagnosis. Recognition of lens dislocation is critical for appropriate management and prevention of vision loss.