Overview Of Night Blindness
Night blindness is poor vision at night or in dim light.
Commonly Associated With
Nyctanopia; Nyctalopia
Considerations
Night blindness may cause problems with driving when it is dark. People with this condition often have trouble seeing stars on a clear night or walking through a dark room, such as a movie theater.
These problems are often worse just after a person is in a brightly lit environment. Milder cases may just have a harder time adapting to darkness.
Causes Of Night Blindness
The causes fall into 2 categories: treatable and non-treatable.
Treatable causes:
- Cataracts
- Nearsightedness
- Use of certain drugs
- Vitamin A deficiency (rare)
Nontreatable causes:
- Birth defects, particularly congenital stationary night blindness
- Retinitis pigmentosa
Exams & Tests
Your provider will examine you and your eyes. The goal of the medical exam is to determine if the problem can be corrected (for example, with new glasses or cataract removal), or if the problem is due to something that is not treatable.
The provider may ask you questions, including:
- How severe is the night blindness?
- When did your symptoms start?
- Did it occur suddenly or gradually?
- Does it happen all the time?
- Does using corrective lenses improve night vision?
- Have you ever had eye surgery?
- What medicines do you use?
- How is your diet?
- Have you recently injured your eyes or head?
- Do you have a family history of diabetes?
- Do you have other vision changes?
- What other symptoms do you have?
- Do you have unusual stress, anxiety, or a fear of the dark?
The eye exam for night blindness will include:
- Color vision testing
- Pupil light reflex
- Refraction
- Retinal exam
- Slit-lamp examination
- Visual acuity
Other tests may be done:
- Electroretinogram (ERG)
- Visual field
Treatment Of Night Blindness
Take safety measures to prevent accidents in areas of low light. Avoid driving a car at night, unless you get your eye doctor’s approval.
Vitamin A supplements may be helpful if you have a vitamin A deficiency. Ask your health care provider.
