Day Blindness is also known as:
- Hemeralopia (medical name), and as
- Night Sight (not to be confused with "Night Blindness")
Day Blindness is the term used to refer to comparatively good vision in poor light but poor vision in good illumination.
An alternative definition of Day Blindness is "a visual defect characterised by the inability to see as clearly in bright light as in dim light".
The meaning of the term Day Blindness is therefore quite easy to remember from its name, though less so when the medical term "Hemeralopia" is used.
Day Blindness is usually congenital (meaning "present since birth"). However, it may sometimes be acquired (meaning occur in a person who did not have the condition previously), for example if the cones in the retina are damaged or destroyed e.g. by disease.
See for comparison Night Blindness.
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.