This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2018, Subject name: Ophthalmology
Mizou-Nakamura phenomenon in fundus is seen in: 
Select and explain. 
A. Congenital rod absence, B. Congenital stationary night blindness, C. Congential cone defect, D. Best disease
B: Congenital stationary night blindness
Answer: B: Congenital stationary night blindness 
Explanation: Congenital stationary night blindness(CSNB) Infantile onset nyctalopia with non progressive retinal dysfunction. Fundus appearance can be normal or abnormal. CSNB with abnormal appearing fundus is known as Oguchi disease. The fundus in oguchi disease is unusual golden yellow in color in light adapted state which becomes normal in color after prolong dark adaptation. This phenomena is known as Mizou-Nakamura phenomena.