The lens is a remarkable structure that plays a critical role in the optical system of the human eye. Dr. Cynthia S. Chiu presents an overview of the lens, including embryologic development, biochemistry, and physiology, providing the foundation to a discussion about diseases of the lens, including presbyopia (age-related loss of lens accommodation) and pediatric- and adult-onset cataract. Cataract surgery has evolved over centuries and new procedures aim to perfect the optical system of the eye in addition to cataract removal. Surgical videos and information on the latest intraocular lens implants, as well as considerations for simultaneous correction of myopia (near-sightedness), hyperopia (far-sightedness), presbyopia, and astigmatism (irregular corneal shape), are featured. Recorded on 10/28/2014. (#28876)