Along with perch, walleye are the other species from the family Percidae of major economic value in Canada. This species is named after its uniquely large, cloudy eyes. The eyes of this species are extremely light-sensitive, and although walleye tolerate a wide range of environmental conditions, they do best in large, shallow, turbid lakes. Walleye avoid the light, and in lakes that are clear, walleye inhabit deeper waters and feed at sunrise, sunset and during the night. A closely related species of fish called the blue walleye formerly inhabited Lake Ontario and Lake Erie. This species was heavily overfished to the point of extinction.