mizuo–nakamura phenomenon mizuo–nakamura phenomenon the mizuo–nakamura phenomenon is a phenomenon observed in oguchi's disease. it was named after gentaro mizuo (1876–1913) and bunpei nakamura (1886–1969), japanese ophthalmologists. oguchi disease is characterized by a golden-brown fundus with a yellow-gray 'metallic' sheen in the light-adapted state. after complete dark adaptation (3 to 12 hours), the fundus appears normal, and this disappearance of the shiny, yellow, fundus reflex is called the mizuo–nakamura phenomenon.