Aging of the human eye lens: Epigenetic landscape and therapeutic targets in age‑related cataracts (Review)

Age‑related cataracts (ARCs) are the predominant cause of blindness globally and are characterized by progressive opacification of the ocular lens. Although oxidative stress, ultraviolet radiation and metabolic dysfunction are well‑documented etiological factors, growing evidence implicates epigenetic dysregulation as a critical pathogenic mechanism in ARCs. Epigenetics refers to heritable changes in gene expression that occur without alterations to the underlying DNA sequence. The primary epigenetic alterations include non‑coding RNAs, DNA methylation, histone modifications, RNA modifications and chromatin remodelling. Epigenetic modifications dynamically regulate gene expression profiles in lens epithelial cells, modulating critical cellular processes such as proliferation, the oxidative stress response and DNA repair, all of which are essential for maintaining lens transparency. Epigenetic research offers novel insights into the molecular mechanisms underlying ARCs and may yield therapeutic strategies targeting dysregulated epigenetic pathways. The present review discusses current evidence on epigenetic mechanisms in ARC pathogenesis, delineating their roles in lens opacity development and highlighting potential targets for clinical intervention.