Where do new lens fibers form?

Where do new lens fibers form?

• A. At the posterior pole
• B. At the equator of the lens
• C. In the central nucleus
• D. Along the anterior capsule

Answer: (B)

New lens fibers form at the equator because this is the germinative zone where the anterior lens epithelium proliferates and then differentiates into elongated fiber cells. These differentiating fibers add to the existing lens by expanding outward from the equator and then stretching inward toward the center, gradually increasing the lens size. The central nucleus is made of fibers formed earlier in development and remains relatively constant in adulthood, while the posterior pole and the anterior capsule do not serve as sites of new fiber formation.

New lens fibers form at the equator because this is the germinative zone where the anterior lens epithelium proliferates and then differentiates into elongated fiber cells. These differentiating fibers add to the existing lens by expanding outward from the equator and then stretching inward toward the center, gradually increasing the lens size. The central nucleus is made of fibers formed earlier in development and remains relatively constant in adulthood, while the posterior pole and the anterior capsule do not serve as sites of new fiber formation.