biconcave lens

例句：

1. 1. The biconcave lens isused to focus light onto a screen.
   双凹透镜用于将光线聚焦到屏幕上。
2. 2.The biconcave lens was designed toimprove the image quality of the camera.
   双凹透镜被设计用来提高相机的图像质量。
3. 3. The biconcave lens isan essential component of many optical instruments.
   双凹透镜是许多光学仪器的重要组成部分。