Frog eye. Light micrograph of a section through the eye of a frog. Most amphibians, such as frogs and salamanders, have color vision, even though they may be restricted to narrower bands of the visible color spectrum than are humans. There are at least four types of photoreceptors or optical sensors with different chemical composition that allow visualisation of different amounts of color by amphibians. Since amphibians have been around a long time and have adapted to a variety of environments, their eye configurations vary slightly for different environments. Amphibian eyes contain photoreceptors like those of some fish. Magnification: x25 when printed at 10 centimetres wide.