Night Blindness is also known as Nyctalopia (medical name).
Night Blindness is the inability, or severely reduced ability, to see in low-light levels, such as at dusk and at night.
Note that those affected can, in the absence of other conditions, see to a normal extent during typical "daytime" light-levels .
Night Blindness is generally due to a disorder of the rods, which are the cells in the retina of the eye that are most important for vision in dim light (i.e. low-light levels, such as occur at night).
There are many possible reasons for a disorder of the rods, leading to Night Blindness.
- Congenital (since birth) Night Blindness
- Deficiency of Vitamin A
- Malabsorption - if it adversely affects absorption of Vitamin A
- Retinitis pigmentosa
- Sorsby's fundus dystrophy (a genetic eye inflammatory disorder.)
- Pathological myopia (myopia ="short-sightedness")
- Peripheral cortical cataract
- Oguchi's disease
More about Ophthalmology:
This section includes short definitions
of many diseases, disorders, and conditions of the eyes and visual system.
For definitions of other terms in this category, choose from the list to the left (but note that this is not a complete/exhaustive list).
Other related pages include
- A diagram of the eye
- Definitions and descriptions of the parts of the eye
- A concise description of the human retina
- Definitions of parts of the retina
- Clinical and surgical procedures re. eyes and human visual system
For further information see also our pages of books about ophthalmology.