Night Blindness – Causes
Night blindness (nyctalopia) is a condition in which there is impaired vision in dim light. The causes of night blindess are:
- Conditions affecting the functioning of rods (as rods are involved in night / scotopic vision)
- Vitamin A deficiency
- Retinitis pigmentosa (and other tapetoretinal degenerations)
- Oguchi disease (congenital stationary night blindness)
- Congenital high mypoia
- Familial congenital night blindness
- Certain conditions affecting transparency of visual media
- In dim light, the pupils dilate so as to allow more light to reach the retina
- In case of peripheral corneal opacities and paracentral lenticular opacities, there is obstruction to the passage of light when pupils are dilated
- Conditions causing delayed dark adaptation
- Advanced primary open angle glaucoma