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