User:Mr. Ibrahem/Visual impairment
| Visual impairment | |
|---|---|
| Other names | Vision impairment, vision loss |
 | |
| A white cane, the international symbol of blindness | |
| Specialty | Ophthalmology |
| Symptoms | Decreased ability to see[1][2] |
| Complications | Non-24-hour sleep–wake disorder, falls in older adults[3][4] |
| Causes | Uncorrected refractive errors, cataracts, glaucoma[5] |
| Diagnostic method | Eye examination[2] |
| Treatment | Vision rehabilitation, changes in the environment, assistive devices (eyeglasses, white cane)[2] |
| Frequency | 940 million / 13% (2015)[6] |
Visual impairment, also known as vision impairment or vision loss, is a decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses.[1][2] Some also include those who have a decreased ability to see because they do not have access to glasses or contact lenses.[1] Visual impairment is often defined as a best corrected visual acuity of worse than either 20/40 or 20/60.[7] The term blindness is used for complete or nearly complete vision loss.[7] Visual impairment may cause difficulties with normal daily activities such as driving, reading, socializing, and walking.[2]
The most common causes of visual impairment globally are uncorrected refractive errors (43%), cataracts (33%), and glaucoma (2%).[5] Refractive errors include near-sightedness, far-sightedness, presbyopia, and astigmatism.[5] Cataracts are the most common cause of blindness.[5] Other disorders that may cause visual problems include age-related macular degeneration, diabetic retinopathy, corneal clouding, childhood blindness, and a number of infections.[8] Visual impairment can also be caused by problems in the brain due to stroke, premature birth, or trauma among others.[9] These cases are known as cortical visual impairment.[9] Screening for vision problems in children may improve future vision and educational achievement.[10] Screening adults without symptoms is of uncertain benefit.[11] Diagnosis is by an eye exam.[2]
The World Health Organization (WHO) estimates that 80% of visual impairment is either preventable or curable with treatment.[5] This includes cataracts, the infections river blindness and trachoma, glaucoma, diabetic retinopathy, uncorrected refractive errors, and some cases of childhood blindness.[12] Many people with significant visual impairment benefit from vision rehabilitation, changes in their environment, and assistive devices.[2]
As of 2015 there were 940 million people with some degree of vision loss.[6] 246 million had low vision and 39 million were blind.[5] The majority of people with poor vision are in the developing world and are over the age of 50 years.[5] Rates of visual impairment have decreased since the 1990s.[5] Visual impairments have considerable economic costs both directly due to the cost of treatment and indirectly due to decreased ability to work.[13]
References[edit]
- ^ a b c "Change the Definition of Blindness" (PDF). World Health Organization. Archived (PDF) from the original on 14 July 2015. Retrieved 23 May 2015.
- ^ a b c d e f g "Blindness and Vision Impairment". February 8, 2011. Archived from the original on 29 April 2015. Retrieved 23 May 2015.
- ^ Auger RR, Burgess HJ, Emens JS, Deriy LV, Thomas SM, Sharkey KM (October 2015). "Clinical Practice Guideline for the Treatment of Intrinsic Circadian Rhythm Sleep-Wake Disorders: Advanced Sleep-Wake Phase Disorder (ASWPD), Delayed Sleep-Wake Phase Disorder (DSWPD), Non-24-Hour Sleep-Wake Rhythm Disorder (N24SWD), and Irregular Sleep-Wake Rhythm Disorder (ISWRD). An Update for 2015: An American Academy of Sleep Medicine Clinical Practice Guideline". Journal of Clinical Sleep Medicine. 11 (10): 1199–236. doi:10.5664/jcsm.5100. PMC 4582061. PMID 26414986.
- ^ Blaylock, SE; Vogtle, LK (June 2017). "Falls prevention interventions for older adults with low vision: A scoping review: Étude de portée sur les interventions visant à prévenir les chutes chez les aînés ayant une basse vision". Canadian journal of occupational therapy. Revue canadienne d'ergotherapie. 84 (3): 139–147. doi:10.1177/0008417417711460. PMID 28730900.
- ^ a b c d e f g h "Visual impairment and blindness Fact Sheet N°282". August 2014. Archived from the original on 12 May 2015. Retrieved 23 May 2015.
- ^ a b Vos T, Allen C, Arora M, Barber RM, Bhutta ZA, Brown A, et al. (GBD 2015 Disease and Injury Incidence and Prevalence Collaborators) (October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
- ^ a b Maberley DA, Hollands H, Chuo J, Tam G, Konkal J, Roesch M, et al. (March 2006). "The prevalence of low vision and blindness in Canada". Eye. 20 (3): 341–6. doi:10.1038/sj.eye.6701879. PMID 15905873.
- ^ GLOBAL DATA ON VISUAL IMPAIRMENTS 2010 (PDF). WHO. 2012. p. 6. Archived (PDF) from the original on 2015-03-31.
- ^ a b Lehman SS (September 2012). "Cortical visual impairment in children: identification, evaluation and diagnosis". Current Opinion in Ophthalmology. 23 (5): 384–7. doi:10.1097/ICU.0b013e3283566b4b. PMID 22805225.
- ^ Mathers M, Keyes M, Wright M (November 2010). "A review of the evidence on the effectiveness of children's vision screening". Child. 36 (6): 756–80. doi:10.1111/j.1365-2214.2010.01109.x. PMID 20645997.
- ^ Siu AL, Bibbins-Domingo K, Grossman DC, Baumann LC, Davidson KW, Ebell M, et al. (March 2016). "Screening for Impaired Visual Acuity in Older Adults: US Preventive Services Task Force Recommendation Statement". JAMA. 315 (9): 908–14. doi:10.1001/jama.2016.0763. PMID 26934260.
- ^ "Causes of blindness and visual impairment". Archived from the original on 5 June 2015. Retrieved 23 May 2015.
- ^ Rein DB (December 2013). "Vision problems are a leading source of modifiable health expenditures". Investigative Ophthalmology & Visual Science. 54 (14): ORSF18-22. doi:10.1167/iovs.13-12818. PMID 24335062.