Night blindness mainly occurs due to interference with the functions of rods owing to deficiency of visual purple. All of the following are causes of night blindness, EXCEPT:

Poor or feeble vision in twilight or in night is known as night blindness or nyctalopia. Causes of night blindness: Xerophthalmia Retinitis pigmentosa High myopia Advanced open-angle glaucoma Disseminated chorioretinal atrophy Oguchi's disease Congenital night blindness Ref: Textbook of Ophthalmology By H V Nema, Nitin Nema, 2012, Page 346.