This articleneeds morereliable medical references forverification or relies too heavily onprimary sources. Please review the contents of the article andadd the appropriate references if you can. Unsourced or poorly sourced material may be challenged andremoved.Find sources: "Blurred vision" – news ·newspapers ·books ·scholar ·JSTOR(June 2022)

An example of blurred vision

Compared to healthy vision

Blurred vision is anocularsymptom where vision becomes less precise and there is added difficulty to resolve fine details.

Temporary blurred vision may involve dry eyes, eye infections,alcohol poisoning,hypoglycemia, orlow blood pressure. Other medical conditions may includerefractive errors such asmyopia, highhypermetropia, andastigmatism,amblyopia,presbyopia,pseudomyopia,diabetes,cataract,pernicious anemia,vitamin B₁₂ deficiency,thiamine deficiency,glaucoma,retinopathy,hypervitaminosis A,migraine,sjögren's syndrome,floater,macular degeneration, and can be a sign ofstroke orbrain tumor.^[1][2][3]

There are many causes of blurred vision:

• Refractive errors: Uncorrected refractive errors likemyopia, highhypermetropia, andastigmatism will cause distance vision blurring.^[1] It is one of the leading cause ofvisual impairment worldwide.^[2] Unless there is no associatedamblyopia, visual blur due to refractive errors can be corrected to normal usingcorrective lenses orrefractive surgeries.^[1]
• Presbyopia due to physiological insufficiency ofaccommodation (accommodation tends to decrease with age) is the main cause of defectivenear vision in the elderly.^[3] Other causes of defective near vision includeaccommodative insufficiency, paralysis of accommodation etc.^[3]
• Pseudomyopia due to accommodation anomalies likeaccommodative excess,accommodative spasm etc. cause distance vision blurring.^[3]
• Alcohol intoxication can cause blurred vision.
• Use ofcycloplegic drugs likeatropine^[4] or other anticholinergics cause visual blur due to paralysis of accommodation.^[3]
• Cataracts: Cloudiness over the eye'slens, cause blurring of vision, halos around lights, and sensitivity to glare.^[5] It is also the main cause of blindness worldwide.^[2]
• Glaucoma: Increasedintraocular pressure (pressure in the eye) cause progressive optic neuropathy that leads tooptic nerve damage,visual field defects and blindness.^[6] Sometimes glaucoma may occur without increased intraocular pressure also.^[6] Some glaucomas (e.g. open angle glaucoma) cause gradual loss of vision and some others (e.g. angle closure glaucoma) cause sudden loss of vision.^[6] It is one of the leading cause of blindness worldwide.^[2]
• Diabetes: Poorly controlled blood sugar can lead to temporary swelling of the lens of the eye, resulting in blurred vision. While it resolves if blood sugar control is reestablished, it is believed repeated occurrences promote the formation of cataracts (which are not temporary).^[7]
• Retinopathy: If left untreated, any type of retinopathy (includingdiabetic retinopathy,hypertensive retinopathy,sickle cell retinopathy, anemic retinopathy,^[8] etc.) can damage retina and lead to visual field defects and blindness.^[9]
• Hypervitaminosis A: Excess consumption of vitamin A can cause blurred vision.^[10]
• Macular degeneration: Macular degeneration cause loss of central vision, blurred vision (especially while reading),metamorphopsia (seeing straight lines as wavy), and colors appearing faded.^[11] Macular degeneration is the third main cause of blindness worldwide, and is the main cause of blindness in industrialised countries.^[12]
• Eye infection,inflammation, orinjury.
• Sjögren's syndrome, achronicautoimmuneinflammatory disease that destroys moisture producing glands, includinglacrimal gland and leads to dry eye and visual blur.^[13]
• Floaters: Tiny particles drifting across the eye. Although often brief and harmless, they may be a sign of retinal detachment.
• Retinal detachment: Symptoms include floaters, flashes of light across your visual field, or a sensation of a shade or curtain hanging on one side of your visual field.
• Optic neuritis: Inflammation of the optic nerve from infection or multiple sclerosis may cause blurring of vision.^[14] There may be pain while moving the eye or touching it through the eyelid.^[14]
• Stroke ortransient ischemic attack
• Brain tumor
• Toxocara: A parasitic roundworm that can cause blurred vision.^[15]
• Bleeding into the eye
• Temporal arteritis: Inflammation of an artery in the brain that supplies blood to the optic nerve.
• Migraine headaches: Spots of light, halos, or zigzag patterns are common symptoms prior to the start of the headache. Aretinal migraine is when you have only visual symptoms without a headache.
• Reduced blinking: Lid closure that occurs too infrequently often leads to irregularities of the tear film due to prolonged evaporation, thus resulting in disruptions in visual perception.
• Carbon monoxide poisoning: Reduced oxygen delivery can affect many areas of the body including vision.^[16] Other symptoms caused by CO includevertigo,hallucination andsensitivity to light.

• Functional visual loss

• Disorders of ocular muscles, binocular movement, accommodation and refraction

• Articles needing additional medical references from June 2022
• All articles needing additional references
• Articles requiring reliable medical sources
• Articles with short description
• Short description is different from Wikidata
• Pages using multiple image with auto scaled images