Carl R. Darnall Army Medical Center - Health Library

Night Blindness

(Nyctanopia; Nyctalopia; Day Sight; Nocturnal Amblyopia)

Definition

Night blindness is difficulty seeing in the dark or in low light. One of the most common issues with night blindness is difficulty driving in the evening or at night.

The Retina of the Eye
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Causes ^

Night blindness is caused by disorders or conditions that affect the cells in the retina that are responsible for vision in dim light (cones). Examples include:

Risk Factors ^

Age is the most common factor that contributes to night blindness. Many eye conditions develop as people get older. Other factors that may increase the chance of night blindness include:

  • Common vision disorders, such as difficulty seeing or focusing on distant objects (nearsightedness)
  • History of eye disorders, such as cataracts, glaucoma, or keratoconus
  • Family history of eye disorders
  • Diabetes (contributes to eye disorders)
  • Medication for glaucoma that constricts (narrows) the pupil
  • Genetic mutations that contribute to eye disorders
  • Not getting adequate amounts of vitamin A, which come from green leafy vegetables, eggs, and whole milk products. Vitamin A deficiency is rare in the United States, but still occurs in certain less developed countries.
  • Disorders that affect the ability of the body to absorb vitamin A:
    • Liver or pancreatic disorders
    • Intestinal conditions
    • Gastric bypass surgery for obesity

Symptoms ^

Symptoms are difficulty or inability to see in low light or darkness, even with glasses or contact lenses. While driving, this may also occur a few seconds after the bright headlights of an oncoming car have passed.

Trouble adjusting from low levels of light to high levels of light

Diagnosis ^

You will be asked about your symptoms and medical history. A complete eye exam will be done. A blood test can be used to test the amount of vitamin A in your blood.

Treatment ^

Treatment depends on the cause of night blindness. Options may include:

  • Taking vitamin A supplements
  • Having cataracts removed
  • Taking medications to treat eye conditions
  • Using low-vision aids and making lifestyle adjustments

Night blindness may require taking extra safety precautions when necessary. This may mean avoiding driving in the evening or at night.

Prevention ^

To help reduce your chance of night blindness:

  • Follow treatment plans for chronic conditions that may contribute to night blindness
  • Have regular eye exams as advised by your eye doctor
  • Eating a diet with adequate amounts of vitamin A
RESOURCES:

American Optometric Association
http://www.aoa.org

Eye Smart—American Academpy of Ophthalmology
http://www.eyesmart.org

CANADIAN RESOURCES:

Canadian Ophthalmological Society
http://www.cos-sco.ca

Health Canada
https://www.canada.ca

REFERENCES:

Glaucoma and driving. Glaucoma Research Foundation website. Available at: http://www.glaucoma.org/treatment/glaucoma-and-driving.php. Updated April 1, 2013. Accessed December 15, 2017.

Night blindness. Cleveland Clinic website. Available at: http://my.clevelandclinic.org/services/cole-eye/diseases-conditions/hic-night-blindness. Updated March 18, 2015. Accessed December 15, 2017.

Night Blindness, Congenital Stationary. The University of Arizona Health Sciences website. Available at: http://disorders.eyes.arizona.edu/disorders/night-blindness-congenital-stationary-csnb1h. Accessed December 15, 2017.

Posterior uveitis. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T326288/Posterior-uveitis. Updated October 11, 2017. Accessed December 15, 2017.

Primary open-angle glaucoma. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T114157. Updated November 22, 2017. Accessed December 15, 2017.

Retinitis pigmentosa. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T116916/Retinitis-pigmentosa. Updated August 2, 2017. Accessed December 15, 2017.

Shedding Light on Night Blindness. American Academy of Ophthalmology Eye Smart website. Available at: https://www.aao.org/eye-health/news/shedding-light-on-night-blindness. Updated September 6, 2016. Accessed December 15, 2017.

Vitamin A deficiency. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T116916/Retinitis-pigmentosa. Updated February 16, 2017. Accessed December 15, 2017.

Last reviewed December 2017 by EBSCO Medical Review Board Michael Woods, MD, FAAP  Last Updated: 12/9/2015