Color Vision in the Paleozoic: Fossil Cones and Rods Found in Gzhelian Pennsylvannian Carboniferous Fish

The finding reveals that such eye cells have existed for at least 300 million years, and that the ancient fish they were discovered in likely saw in color, according to the study's scientists.

Human vision depends on pigments that absorb light. These pigments lie inside cells known as rods and cones. Cones are sensitive to color and also help perceive fine detail and rapid changes. Rods are more sensitive to light than cones, but are not sensitive to color, and are responsible for peripheral and night vision. Both rods and cones are found in a layer of tissue in the back of the eye known as the retina. [Vision Quiz: What Can Animals See?]

Myllokunmingia may be one of the earliest known creatures with a backbone, and this creature may have possessed a rudimentary cameralike eye, which suggests vision dates back at least 520 million years. However, much remains unknown about the evolution of vision, since the soft tissue of the eye usually decays rapidly after death.

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