延焦人工水晶的光學設計與影像品質評估

Abstract

本研究針對延展焦深人工水晶體進行光學設計與成像品質評估，旨在解決傳統單焦與多焦人工水晶體存在的視力不穩定、色差與光暈問題。研究採用Liou & Brennan人眼模型為基礎，結合Zemax光學模擬進行延焦型人工水晶體的設計，特別著重後曲面繞射結構與前曲面非球面優化。 在材料方面，選用PH30S水凝膠，並藉由光譜儀量測其折射率與阿貝數，再導入光學模擬模型中，提升設計準確性。後曲面設計部分則導入改良正弦相位函數來控制不同繞射階數的能量分佈，前曲面則利用Binary 2自由曲面公式進行優化，使成像表現在不同距離上達到平衡，降低視覺切換帶來的不適。 實驗結果顯示，所設計之延展焦深人工水晶體能有效延展視覺焦深，在遠、中、近三距離皆提供穩定的視覺品質，並藉由調制轉換函數分析驗證其高對比度成像能力；同時，在降低色差與光暈現象上亦具明顯改善。整體而言，本研究提出之延展焦深人工水晶體設計兼具光學效能與材料可行性，未來可望提升白內障患者的術後生活品質，並提供臨床應用新選擇。

This study focuses on the optical design and imaging quality evaluation of Extended Depth of Focus (EDOF) intraocular lenses (IOLs), aiming to address the issues of visual instability, chromatic aberration, and halo effects commonly found in traditional monofocal and multifocal IOLs. Based on the Liou & Brennan eye model and using Zemax optical simulation software, the design emphasizes optimization of the posterior diffractive surface and anterior aspheric surface. In terms of material, PH30S hydrogel was selected. Its refractive index and Abbe number were measured using a spectrophotometer and then imported into the optical simulation to improve design accuracy. The posterior surface design incorporated a modified sinusoidal phase function to control energy distribution among diffraction orders, while the anterior surface was optimized using the Binary 2 freeform surface formula to achieve balanced imaging performance across various distances and reduce visual discomfort during focus transitions. Experimental results show that the designed EDOF IOL effectively extends the visual depth of focus, providing stable image quality at far, intermediate, and near distances. High contrast imaging performance was verified through Modulation Transfer Function (MTF) analysis. Additionally, significant improvements in reducing chromatic aberration and halo effects were observed. Overall, the proposed EDOF IOL design demonstrates both optical efficacy and material feasibility, with strong potential to enhance postoperative visual outcomes for cataract patients and offer a new clinical solution.