人工晶状体 (IOL) 是在眼中，因为它玷污了由白内障手术，或作为一种形式的屈光手术改变了眼内的光功率通常更换现有的水晶体植入式的镜头。它通常包括一个小的塑料镜头与塑料侧高视阔步，称为触觉，在眼球内囊袋内地方举行镜头。[引证需要]Iol 传统上了坚定的材料 (PMMA)，虽然这很大程度上已被使用的柔性材料取代。今天安装的大多数 Iol 被固定的  镜片匹配到距离视觉。然而，其他类型都可用，多焦点 Iol，为病人提供多集中视觉远和阅读距离和自适应 Iol，为病人提供有限的视觉住宿等。

"a manual usually accompanying a technical device and explaining how to install or operate it" Essential Requirements - Medical Device Directive 93/42/EEC - Annex I, 13.1: Each device must be accompanied by the information needed to use it safely and to identify the manufacturer, taking account of the training and knowledge of the potential user. This information comprises the details on the label and the data in the instructions for use. As far as practicable and appropriate, the information needed to use the device safely must be set out on the device itself and/or on the packaging of each unit. If not practicable, the information must be set out in the leaflet supplied with one or more devices. Instructions for use must be included in the packaging for every device. By way of exception, no such instruction leaflet is needed for devices in Class I or Class IIa if they can be used completely safely without any such instructions.