BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuVision - night blindnessNyctanopia; Nyctalopia; Night blindnessNight blindness is poor vision at night or in dim light. Considerations Night blindness may cause problems with driving at night. People with night blindness 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 The causes of night blindness fall into 2 categories: treatable and nontreatable.Treatable causes:Cataracts CataractsA cataract is a clouding of the lens of the eye.ImageRead Article Now Book Mark Article Nearsightedness NearsightednessNearsightedness is when light entering the eye is focused incorrectly. This makes distant objects appear blurred. Nearsightedness is a type of refr...ImageRead Article Now Book Mark Article Use of certain drugs Vitamin A deficiency (rare)Vitamin A deficiencyVitamin A is a fat-soluble vitamin that is stored in the liver. There are two types of vitamin A that are found in the diet. Preformed vitamin A is f...ImageRead Article Now Book Mark Article Nontreatable causes:Birth defects, particularly congenital stationary night blindness Retinitis pigmentosaRetinitis pigmentosaRetinitis pigmentosa is an eye disease in which there is damage to the retina. The retina is the layer of tissue at the back of the inner eye. This...ImageRead Article Now Book Mark Article Home Care 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 how much you should take, because it is possible to take too much. When to Contact a Medical Professional It is important to have a complete eye exam to determine the cause, which may be treatable. Contact your eye doctor if symptoms of night blindness persist or significantly affect your life. What to Expect at Your Office Visit 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.Cataract removalCataract removal is surgery to remove a clouded lens (cataract) from the eye. Cataracts are removed to help you see better. The procedure almost al...ImageRead Article Now Book Mark Article 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? DiabetesDiabetes is a long-term (chronic) disease in which the body cannot regulate the amount of sugar in the blood.ImageRead Article Now Book Mark Article 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 will include:Color vision testing Pupil light reflex Refraction Retinal exam Slit lamp examination Slit lamp examinationThe slit-lamp examination looks at structures that are at the front of the eye.ImageRead Article Now Book Mark Article Visual acuity Other tests may be done:Electroretinogram (ERG) ElectroretinogramElectroretinography is a test to measure the electrical response of the eye's light-sensitive cells, called rods and cones. These cells are part of ...ImageRead Article Now Book Mark Article Visual fieldVisual fieldThe visual field refers to the total area in which objects can be seen in the side (peripheral) vision as you focus your eyes on a central point. Thi...ImageRead Article Now Book Mark Article Open ReferencesReferencesCao D. Color vision and night vision. In: Sadda SVR, Sarraf D, Freund KB, et al, eds. Ryan's Retina.7th ed. Philadelphia, PA: Elsevier; 2023:chap 11.Cukras CA, Zein WM, Caruso RC, Sieving PA. Progressive and "stationary" inherited retinal degenerations. In: Yanoff M, Duker JS, eds. Ophthalmology. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 6.14.Duncan JL, Pierce EA, Laster AM, et al. Inherited retinal degenerations: current landscape and knowledge gaps. Transl Vis Sci Technol. 2018;7(4):6. PMID: 30034950 pubmed.ncbi.nlm.nih.gov/30034950/.Fenner BJ, Tan TE, Barathi AV, et al. Gene-based therapeutics for inherited retinal diseases. Front Genet. 2022;12:794805. PMID: 35069693 pubmed.ncbi.nlm.nih.gov/35069693/.Thurtell MJ, Prasad S, Tomsak RL. Neuro-ophthalmology: afferent visual system. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 16.AllVideoImagesTogExternal and internal eye anatomy - illustration The cornea allows light to enter the eye. As light passes through the eye the iris changes shape by expanding and letting more light through or constricting and letting less light through to change pupil size. The lens then changes shape to allow the accurate focusing of light on the retina. Light excites photoreceptors that eventually, through a chemical process, transmit nerve signals through the optic nerve to the brain. The brain processes these nerve impulses into sight.External and internal eye anatomyillustrationExternal and internal eye anatomy - illustration The cornea allows light to enter the eye. As light passes through the eye the iris changes shape by expanding and letting more light through or constricting and letting less light through to change pupil size. The lens then changes shape to allow the accurate focusing of light on the retina. Light excites photoreceptors that eventually, through a chemical process, transmit nerve signals through the optic nerve to the brain. The brain processes these nerve impulses into sight.External and internal eye anatomyillustrationRelated Information Review Date: 8/22/2022 Reviewed By: Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. 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Vision - night blindnessNyctanopia; Nyctalopia; Night blindnessNight blindness is poor vision at night or in dim light. Considerations Night blindness may cause problems with driving at night. People with night blindness 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 The causes of night blindness fall into 2 categories: treatable and nontreatable.Treatable causes:Cataracts CataractsA cataract is a clouding of the lens of the eye.ImageRead Article Now Book Mark Article Nearsightedness NearsightednessNearsightedness is when light entering the eye is focused incorrectly. This makes distant objects appear blurred. Nearsightedness is a type of refr...ImageRead Article Now Book Mark Article Use of certain drugs Vitamin A deficiency (rare)Vitamin A deficiencyVitamin A is a fat-soluble vitamin that is stored in the liver. There are two types of vitamin A that are found in the diet. Preformed vitamin A is f...ImageRead Article Now Book Mark Article Nontreatable causes:Birth defects, particularly congenital stationary night blindness Retinitis pigmentosaRetinitis pigmentosaRetinitis pigmentosa is an eye disease in which there is damage to the retina. The retina is the layer of tissue at the back of the inner eye. This...ImageRead Article Now Book Mark Article Home Care 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 how much you should take, because it is possible to take too much. When to Contact a Medical Professional It is important to have a complete eye exam to determine the cause, which may be treatable. Contact your eye doctor if symptoms of night blindness persist or significantly affect your life. What to Expect at Your Office Visit 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.Cataract removalCataract removal is surgery to remove a clouded lens (cataract) from the eye. Cataracts are removed to help you see better. The procedure almost al...ImageRead Article Now Book Mark Article 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? DiabetesDiabetes is a long-term (chronic) disease in which the body cannot regulate the amount of sugar in the blood.ImageRead Article Now Book Mark Article 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 will include:Color vision testing Pupil light reflex Refraction Retinal exam Slit lamp examination Slit lamp examinationThe slit-lamp examination looks at structures that are at the front of the eye.ImageRead Article Now Book Mark Article Visual acuity Other tests may be done:Electroretinogram (ERG) ElectroretinogramElectroretinography is a test to measure the electrical response of the eye's light-sensitive cells, called rods and cones. These cells are part of ...ImageRead Article Now Book Mark Article Visual fieldVisual fieldThe visual field refers to the total area in which objects can be seen in the side (peripheral) vision as you focus your eyes on a central point. Thi...ImageRead Article Now Book Mark Article Open ReferencesReferencesCao D. Color vision and night vision. In: Sadda SVR, Sarraf D, Freund KB, et al, eds. Ryan's Retina.7th ed. Philadelphia, PA: Elsevier; 2023:chap 11.Cukras CA, Zein WM, Caruso RC, Sieving PA. Progressive and "stationary" inherited retinal degenerations. In: Yanoff M, Duker JS, eds. Ophthalmology. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 6.14.Duncan JL, Pierce EA, Laster AM, et al. Inherited retinal degenerations: current landscape and knowledge gaps. Transl Vis Sci Technol. 2018;7(4):6. PMID: 30034950 pubmed.ncbi.nlm.nih.gov/30034950/.Fenner BJ, Tan TE, Barathi AV, et al. Gene-based therapeutics for inherited retinal diseases. Front Genet. 2022;12:794805. PMID: 35069693 pubmed.ncbi.nlm.nih.gov/35069693/.Thurtell MJ, Prasad S, Tomsak RL. Neuro-ophthalmology: afferent visual system. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 16.