Fundus image processing device and non-transitory computer-readable storage medium storing computer-readable instructions

A non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a processor of a fundus image processing device that processes a fundus image of a subject eye, cause the fundus image processing device to perform the steps of:

• (a) acquiring the fundus image photographed by a fundus image photographing device;
• (b) acquiring a blood vessel image that indicates at least one of an arteriole and a venule in the fundus image by inputting the fundus image into a mathematical model trained by a machine learning algorithm;
• and
• (c) acquiring a blood vessel area that is an area of at least one of the arteriole and the venule in the whole of the blood vessel image acquired in the step of (b).