Refractive surgery: how far can technology correct vision?

Abstract

Introduction: Refractive surgery represents an important advance in modern ophthalmology, allowing the correction of different refractive errors through progressively more precise and individualized techniques. Procedures such as photorefractive keratectomy (PRK), in situ laser-assisted keratomyleusis (LASIK) and small incision lenticulum extraction (SMILE), associated with topography, tomography and aberrometry technologies, have expanded the possibilities of treating myopia, hyperopia and astigmatism. However, the correction capacity remains conditioned by the anatomical and biomechanical characteristics of the eye. Objective: The evolution of refractive surgery, its main techniques, correction possibilities, limitations and current challenges was described, highlighting the extent to which technology can modify the ocular optical system safely and predictably. This is a narrative, descriptive, and qualitative review of the literature on refractive surgery. Methods: This is a narrative review of the literature, with a qualitative approach and descriptive purpose, aimed at analyzing scientific evidence on refractive surgery and correction of refractive errors. The search was carried out between 1998 and 2025 in the PubMed/MEDLINE, SciELO, LILACS, Virtual Health Library (VHL) and Scopus databases, using descriptors related to phakic intraocular lenses and ophthalmological conditions, such as myopia, hyperopia, astigmatism and presbyopia AND and OR. After analyzing the references and available content, the information was organized according to authorship, year, objective, design and main findings. The synthesis was conducted in a descriptive and interpretative manner, with emphasis on the comparison of surgical techniques, clinical indications, visual results, safety of procedures and factors that influence therapeutic choice. Results: Technological evolution has allowed greater precision in the planning and execution of refractive procedures, enabling personalized treatments of different degrees of myopia, hyperopia, and astigmatism. Detailed preoperative evaluation, including analysis of corneal thickness, curvature, topography, and biomechanics, has become essential for patient selection. In high degrees, alternatives such as phakic intraocular lenses can expand the therapeutic possibilities. Despite the advances, limitations remain related to visual quality, optical aberrations, ocular surface, corneal biomechanics, and presbyopia. Adverse effects such as dry eye, halos, and changes in night vision may also occur. Conclusion: Refractive surgery has a high capacity to reduce dependence on optical correction, but is not able to fully reproduce natural visual function in all conditions. Its limits are determined by the interaction between technology, ocular anatomy, safety, and individual biological response.