Revolutionizing contact lens manufacturing: exploring cutting-edge techniques and innovations for enhanced vision and comfort

This review paper delves into the advancements and innovations revolutionizing contact lens (CL) manufacturing, focusing on techniques and technologies aimed at improving vision quality and wearer comfort. The article begins by tracing the evolution of CL fabrication techniques, paying homage to Leonardo da Vinci's early contributions. It then discusses traditional methods such as lathe-cutting, spincasting, molded lens fabrication, and the recent advent of 3D printing in CL production. The review further explores advanced CL designs, including spherical, aspheric, toric, and bifocal/multifocal CLs, highlighting their specific applications and benefits. Material innovations in lens manufacturing are examined, with an emphasis on silicone hydrogel CL, hybrid lenses combining different materials, and the development of biocompatible and gas-permeable (GP) materials. Evaluation of optical design efficiency is another crucial aspect covered in this paper, encompassing visual acuity, contrast sensitivity, through-focus curves, reading performance, peripheral refraction, and patient-reported outcomes for quality of vision. Additionally, the role of nanotechnology and surface modifications in enhancing lens properties is explored, along with advances in lens coating and surface treatments, including antimicrobial and UV protection coatings. Nanocomposites of polymethyl methacrylate (PMMA) and TiO2 showed refractive indices between 1.52 and 1.59, while combining TiO2 NPs with poly(2-hydroxyethyl methacrylate) (PHEMA) yielded values ranging from 1.47 to 1.53. PGMA-TiO2 nanocomposites exhibited refractive indices between 1.47 and 1.50. Furthermore, nanocomposites of PVP-PVA-Ag with silver (Ag) NPs achieved higher refractive indices within the range of 1.45 to 1.49. This article concludes by discussing the challenges and future directions in CL manufacturing, focusing on addressing lens discomfort, improving oxygen permeability and moisture retention, and enhancing manufacturing efficiency and scalability. Overall, this review offers valuable insights into the cutting-edge techniques and innovations transforming CL production and paving the way for improved vision correction and wearer satisfaction.