The human lens undergoes a continuous transformation with age, progressively compromising its structure, function, and optical performance. This chapter explores dysfunctional lens syndrome (DLS) as a progressive condition characterized by anatomical transformations, gradual decline in lens transparency, higher-order aberrations, and reduced accommodative ability. Refractive lens exchange (RLE) is highlighted as a pivotal solution, effectively addressing both refractive errors and lens dysfunction, with a careful evaluation of its benefits and personalized risks. The discussion concludes with a comprehensive review of cataracts, examining their distinct types and the potential complications they entail, emphasizing the critical balance between risks and outcomes in lens replacement strategies.