Adaptive features of aquatic mammals' eye.

Abstract in brief

• Aquatic mammals have specialized eyes that adapt for clear vision both underwater and in the air, including unique anatomy and optical features.
• They typically focus light on their retinas (emmetropia) both underwater and above water, employing mechanisms like iris muscle control and reflective structures to adjust to different light conditions.
• Their retinas mainly contain rod cells for low-light vision, with specialized structures like large ganglion cells and specific ganglion cell areas that optimize their ability to see clearly in the aquatic environment.