为了使白内障患者在术后获得良好的视觉效果,提出一种扩展焦深的双区域非球面衍射人工晶状体(IOL)设计。在Zemax软件中基于无晶状体眼模型对其进行了优化和分析。分析结果表明,在±4°的视场内,从0.75 m到无穷远的物距,佩戴此人工晶体的人眼模型在550 nm波长、2.5 mm瞳孔直径的条件下调制传递函数(MTF)值在空间频率为50 cycles·mm -1时保持在0.30以上。对角膜非球面系数的变化进行了蒙特卡罗分析,结果表明,当角膜非球面系数在-0.70~0.60的范围内变化时,从0.75 m到无穷远的物距,空间频率为50 cycles·mm -1处约有90%的MTF大于0.29。此外,理论分析表明,所设计的人工晶体在不同瞳孔和白光照明的情况下,其成像性能基本保持稳定。

To obtain a continuous range of clear vision in pseudophakia, an intraocular lens (IOL) with a dual-area aspheric surface and an extended depth of focus was proposed. The IOL was optimized based on a model of aphakia, and its optical performance was analyzed using Zemax. The modulation transfer function (MTF) values remained >0.30 at 50 cycles·mm ^-1 for eyes with a pupil diameter of 2.5 mm and object distance ranging from 0.75 m to infinity at a full field of view of ±4° and wavelength of 550 nm. Monte Carlo analysis showed that the MTF value at 50 cycles·mm ^-1 was >0.29, with a probability of 90% for eyes with anterior corneal asphericity ranging from -0.70 to 0.60 when the object distance ranged from 0.75 m to infinity. In addition, theoretical analysis showed that the optical performance remained stable at different pupil diameters and in polychromatic light.