You’re eyeball to eyeball with a walleye surfperch. I love the yellow streak on the upper part of the iris. One of the ways we identify the walleye is by its large eye.
Honestly, the eye doesn’t seem that large when viewed on live specimens in the wild. When I encountered a large male I got the idea to measure the proportional size of the eye and compare it with that of a close relative, the silver surf perch. I measured the height and length of the eye and the head, then calculated the ratio. In a fish with a proportionally bigger eye, the eye:head ratio will be a larger number. Here are the results. Length: walleye = .33; silver = .22. Height: walleye = .38; silver = .34. The walleye has a proportionally larger eye, especially in the length dimension. The field guides are correct!