A comprehensive schematic eye model of the hooded merganser is introduced for the first time to advance the understanding of amphibious vision. It is comprised of two different configurations, the first one modeling its visual system in air (unaccommodated state) and the second one representing the case where the eye is immersed in water (accommodated state). The model was designed using available data of former studies, image analysis and the implementation of feasible assumptions that serve as starting values. An optimization process incorporating an optical design program is used to vary the starting values with the aim of finding the setup offering the best acuity. The image quality was measured using the root-mean-square radius of the focal spot formed on the retina. The resulting schematic eye model comprises all relevant optical specifications, including aspherical geometrical parameters for cornea and lens, distances between the surfaces, the gradient index distribution of the lens, the retinal specifications and the object distance in both media. It achieves a spot radius of 4.20 $\mathrm{\mu }$m for the unaccommodated state, which meets the expectations derived by the mean ganglion cell density and comparison with other animals. In contrast, under water the determined spot radius of 11.48 $\mathit{\mu }$m indicates an acuity loss. As well as enhancing our understanding of the vision of the hooded merganser, the schematic eye model may also serve as a simulation basis for examing similar animal eyes, such as the cormorant or other fish hunting birds.

首次介绍了蒙面秋沙鸭的综合示意图眼模型，以促进对两栖视觉的理解。它由两种不同的配置组成，第一种是模拟空气中的视觉系统（未调节状态），第二种是表示眼睛浸入水中的情况（调节状态）。该模型是使用以前研究的可用数据、图像分析和作为起始值的可行假设的实施而设计的。结合光学设计程序的优化过程用于改变起始值，目的是找到提供最佳敏锐度的设置。使用在视网膜上形成的焦斑的均方根半径来测量图像质量。由此产生的示意性眼睛模型包括所有相关的光学规格，包括角膜和晶状体的非球面几何参数、表面之间的距离、晶状体的梯度指数分布、视网膜规格和两种介质中的物距。它实现了 4.20 的光斑半径 $\mathrm{\mu }$m 表示未调节状态，符合平均神经节细胞密度和与其他动物比较得出的预期。相比之下，在水下确定的光斑半径为 11.48 $\mathit{微米}$m 表示视力下降。除了增强我们对蒙面秋沙鸭视觉的理解之外，示意图眼模型还可以作为检查类似动物眼睛的模拟基础，例如鸬鹚或其他猎鱼鸟类。