Visual Function
VEHSS reports the prevalence of Visual Function indicators as the proportion or persons or patients in each dataset with each visual function category or response value, based on survey-self reported vision or function, objectively measured visual acuity, or diagnosed low vision.
Measured Visual Acuity
VEHSS includes measured visual acuity from published examination studies, examination surveys and EHR registries. Further details of examination-based indicators from surveys and published sources are available in the following technical documentation:
VEHSS Survey Analysis Plan CDC pdf icon[PDF – 480 KB]external icon
VEHSS Claims and Registry Data Analysis Plan CDC pdf icon[PDF – 580 KB]external icon
Literature Review of Examination-Based Studies CDC pdf icon[PDF – 1.4 MB]external icon
Diagnosis Code Indicators
The VEHSS system uses diagnosis codes to identify vision and eye disorders in all administrative claims and electronic medical registry data. Diagnosis codes are based on the International Classification of Diseases (ICD) system. All ICD-9 and ICD-10 codes related to vision, the eye, and ocular adnexa are categorized in a two-level categorization system using mutually exclusive categories and sub-groups to provide more efficient estimates of key vision and eye health outcomes.
VEHSS Diagnosis Code Categories and Crosswalk CDC pdf icon[PDF – 2.1 MB]external icon This report includes the ICD-9 and ICD-10 codes mapped to each category and subgroup. Updated spreadsheet versions of this crosswalk are available upon request.
VEHSS Claims and Registry Data Analysis Plan CDC pdf icon[PDF – 580 KB]external icon This report details VEHSS’ approach to utilizing administrative claims and registry data to create systematic single-source estimates.
Other Visual Disturbances includes indicators representing both Visual Function and Eye Health Conditions. VEHSS includes indicators of Other Visual Disturbances from claims databases and IRIS Registry.
Diagnosed or Treated
Blindness or Low Vision includes diagnosis codes indicating low vision or blindness in two types of data sources:
- Diagnosed prevalence: IRIS Registry indicates Diagnosed conditions that exists in the patient’s medical record.
- Treated prevalence: Administrative claims databases indicate Treated conditions for which a diagnosis code was included anywhere on a submitted bill.
Diagnosed or Treated Blindness or Low Vision is indicated by a patient having one or more diagnosis codes indicating one or more of the blindness or low vision subgroups listed below.
| Subgroup | Indicated conditions |
|---|---|
| Unqualified visual loss, both eyes | Unqualified vision loss, both eyes includes a diagnosis code indicating unqualified visual loss in both eyes. |
| Unqualified vision loss in one eye, or unspecified visual loss | Unqualified vision loss in one eye or unspecified vision loss includes diagnosis codes indicating unqualified vision loss in one eye, unspecified visual loss, or problems with sight. |
| Low vision or blindness, one eye | Low vision or blindness in one eye includes diagnosis codes indicating low vision or blindness in one eye, normal vision in the other eye. |
| Blindness one eye, low vision other eye | Blindness in one eye, low vision in other eye includes diagnosis codes indicating blindness in one eye, low vision in other eye. |
| Low vision, both eyes | Low vision, both eyes includes diagnosis codes indicating low vision in both eyes. |
| Blindness, both eyes, including legal blindness | Blindness, both eyes, including legal blindness includes diagnosis codes indicating blindness in both eyes, legal blindness, or cortical blindness. |
Full lists of ICD9 and ICD10 codes: VEHSS diagnosis codes reportpdf iconexternal icon
| Dataset | Years analyzed | Reporting type |
|---|---|---|
| IRIS | 2016, 2017, 2018 | Diagnosed |
| Medicaid MAX | 2013, 2014 | Treated |
| Medicare 100% FFS claims | 2014, 2015, 2016, 2017 | Treated |
| Managed Vision Care | 2016 | Treated |
| MarketScan commercial insurance | 2016 | Treated |
VEHSS includes indicators of Far-Distance Visual Function from self-report surveys.
Self-reported
Self-reported Far-Distance Visual Function indicates the respondent replied that they have difficulty with tasks that require good distance vision.
| Dataset | Description | Question Text | Variable name(s) | Years available | Years analyzed | Response options |
|---|---|---|---|---|---|---|
| NHIS | Percentage of adults who even when wearing glasses or contact lenses find it (not at all, only a little, somewhat, or very) difficult to drive during daytime in familiar places (NHIS Adult Module) | Even when wearing glasses or contact lenses, because of your eyesight, how difficult is it for you…to drive during daytime in familiar places? | DRV, AVDFDRV, AVDF_DRV |
1999, 2002, 2008, 2016, 2017 |
2016, 2017 | 0 Not at all difficult 1 Only a little difficult 2 Somewhat difficult 3 Very difficult 4 Can’t do at all (because of eyesight; 2008) 6 Do not do this activity (for other reasons; 2008) 7 Refused 8 Not ascertained (2008) 9 Don’t know |
| NHIS | Percentage of adults who wear eyeglasses or contact lenses to drive, read road and street signs, watch TV, or see things in the distance (NHIS Adult Module) | Do you wear eyeglasses or contact lenses to drive, read road and street signs, watch TV, or see things in the distance? | VIMDRIVE | 2016, 2017 | 2016, 2017 | 1 Yes 2 No 7 Refused 8 Not ascertained 9 Don’t know |
| NHIS | Percentage of children who wear eyeglasses or contact lenses to read road and street signs, see the blackboard, play sports, watch TV, or see things in the distance (NHIS Child Module) | Does [fill: SC name] wear eyeglasses or contact lenses to read road and street signs, see the blackboard, play sports, watch TV, or see things in the distance? | CVISDIST | 2008, 2016, 2017 | 2016, 2017 | 1 Yes 2 No 7 Refused 9 Don’t know |
| NHIS | Percentage of children who can read the board from the back of the classroom (NHIS Child Module) | Can [fill1: S.C. name] read the board from the back of the classroom? | CVISRD | 2008, 2016, 2017 | 2016, 2017 | 1 Yes 2 No 7 Refused 9 Don’t know |
VEHSS includes indicators of Functional Difficulty from self-report surveys.
Self-reported
Self-reported Functional Difficulty indicates the respondent replied that they have difficulty completing functional tasks due to vision.
| Dataset | Description | Question text | Variable name(s) | Years available | Years analyzed | Response options |
|---|---|---|---|---|---|---|
| NHIS | Percentage of adults who even when wearing glasses or contact lenses find it (not at all, only a little, somewhat, or very) difficult to find something on a crowded shelf (NHIS Adult Module) | Even when wearing glasses or contact lenses, because of your eyesight, how difficult is it for you…to find something on a crowded shelf? | CRD, AVDFCRD, AVDF_CRD | 1999, 2002, 2008, 2016, 2017 | 2016, 2017 | 0 Not at all difficult 1 Only a little difficult 2 Somewhat difficult 3 Very difficult 4 Can’t do at all (because of eyesight; 2008) 6 Do not do this activity (for other reasons; 2008) 7 Refused 8 Not ascertained (2008) 9 Don’t know |
Measured Visual Acuity refers to measured acuity in the better-seeing eye using eye charts, autorefractors, and other methods. Measured Visual Acuity includes the following types:
- Best corrected: Measured with optimal correction.
- Presenting: Measured using a patient or respondents’ glasses or contacts they were wearing at the time of the exam.
- Uncorrected refractive error: Calculated as patients with ≤20/50 presenting, but improve to ≤20/40 best corrected.
NHANES, IRIS Registry, and published examination studies include measured visual acuity.
VEHSS classifies each type of visual acuity based on the following scale:
| Description | Definition |
|---|---|
| Normal Vision | 20/12.5 – 20/25 (better-seeing eye) |
| Any Vision Loss | ≤20/32 (better-seeing eye) |
| Visual Impairment | 20/32 – 20/160 (better-seeing eye) |
| US Defined Blindness | ≤20/200 (better-seeing eye) |
| World Health Organization (WHO) Defined Blindness | ≤20/400 (better-seeing eye) |
| Monocular Vision Loss | ≤20/70 in worse eye, mild or normal in better-seeing eye |
| Uncorrected Refractive Error | ≤20/50 (presenting in better-seeing eye, improving to >20/40 with correction) |
| Missing Acuity | No acuity measure classified above |
| Dataset | Description | Variables | Years available | Years analyzed | Response options |
|---|---|---|---|---|---|
| IRIS Registry | Best-corrected visual acuity | Best corrected acuity | 2014-2016 | 2016 | Normal Vision Any Vision Loss Visual Impairment US-defined Blindness Monocular Vision Loss |
| NHANES | Best-corrected visual acuity | VIDROVA – Right visual acuity, w/ obj. refraction; |
1999-2008 | 1999-2008 | Normal Vision Any Vision Loss Visual Impairment US-defined Blindness Monocular Vision Loss |
| VIDLOVA – Left visual acuity, w/ obj. refraction |
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| VIQ017-Blind in both eyes* | |||||
| NHANES | Presenting visual acuity | VIDRVA – Right visual acuity, presenting; | 1999-2008 | 1999-2008 | Presenting with normal vision Presenting with any vision loss Presenting with visual impairment Presenting with US-defined blindness Presenting with monocular vision loss |
| VIDLVA – Left visual acuity, presenting |
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| VIQ017-Blind in both eyes* | |||||
| NHANES | Uncorrected Refractive Error (URE) | VIDRVA – Right visual acuity, presenting; | 1999-2008 | 1999-2008 | Uncorrected Refractive Error (URE) |
| VIDLVA – Left visual acuity, presenting; |
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| VIDROVA – Right visual acuity, w/ obj. refraction; |
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| VIDLOVA – Left visual acuity, w/ obj. refraction |
VEHSS uses data from the following published estimates of blindness and low vision to create multi-source prevalence estimates. Please see the VEHSS literature review for details and other published studies.
| Study | Years | Location | Citation |
|---|---|---|---|
| Baltimore Pediatric Eye Study (BPEDS) | 2003-2007 | Maryland | Friedman D, Repka M, Katz J, et al. Prevalence of Decreased Visual Acuity among Preschool Aged Children in an American Urban Population: The Baltimore Pediatric Eye Disease Study, Methods and Results. Ophthalmology. 2008:115(10):1786-1795. |
| Chinese American Eye Study (CHES) | 2010-2013 | California | Varma R, Kim JS, Burkemper BS, et al. Prevalence and Causes of Visual Impairment and Blindness in Chinese American Adults: The Chinese American Eye Study. JAMA Ophthalmol.2016;134(7):785–793. |
| Eye Diseases Prevalence Research Group (EDPRG) | 1990-2001 | National | The Eye Diseases Prevalence Research Group. Causes and prevalence of visual impairment among adults in the United States. Arch Ophthalmol. 2004;122:477–485. |
| Los Angeles Latino Eye Study (LALES) | 2000-2003 | California | Varma R, Ying-Lai M, Klein R, Azen SP; G. Los Angeles Latino Eye Study. Prevalence and risk indicators of visual impairment and blindness in Latinos: The Los Angeles Latino Eye Study. Ophthalmology. 2004;111(6):1132–1140. |
| Multi-ethnic Study of Atherosclerosis (MESA) | 2002-2004 | National | Fisher DE, Shrager S, Shea SJ, et al. Visual Impairment in White, Chinese, Black, and Hispanic Participants from the Multi-Ethnic Study of Atherosclerosis Cohort. Ophthalmic Epidemiol. 2015;22(5):321–332. |
| Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) | 1980-2007 | Wisconsin | Klein R, Lee KE, Knudtson MD, Gangon RE, Klein BE. Changes in Visual Impairment Prevalence by Period of Diagnosis of Diabetes: The Wisconsin Epidemiologic Study of Diabetic Retinopathy. Ophthalmology. 2009;116(10):1937–1942. |
VEHSS includes indicators of Near-Distance Visual Function from self-report surveys.
Self-reported
Self-reported Near-Distance Visual Function indicates the respondent replied that they have difficulty with tasks that require good near distance vision.
| Dataset | Description | Question text | Variable name(s) | Years available | Years analyzed | Response options |
|---|---|---|---|---|---|---|
| NHIS | Percentage of adults who wear eyeglasses or contact lenses to read books or newspaper, write, or other things that require them to see well up close (NHIS Adult Module) | Do you wear eyeglasses or contact lenses to read books or newspapers, write, or do other things that require you to see well up close, such as cooking, sewing or fixing things? | VIMREAD | 2008, 2016, 2017 | 2016, 2017 | 1 Yes 2 No 7 Refused 9 Don’t know |
| NHIS | Percentage of adults who even when wearing glasses or contact lenses find it (not at all, only a little, somewhat, or very) difficult to read ordinary print in newspapers (NHIS Adult Module) | Even when wearing glasses or contact lenses, because of your eyesight, how difficult is it for you…to read ordinary print in newspapers? | NWS, AVDF_NWS | 1999, 2002, 2008, 2016, 2017 | 2016, 2017 | 0 Not at all difficult 1 Only a little difficult 2 Somewhat difficult 3 Very difficult 4 Can’t do at all because of eyesight 6 Do not do this activity for other reasons 7 Refused 9 Don’t know |
| NHIS | Percentage of adults who when wearing glasses or contact lenses find it (not at all, only a little, somewhat, or very) difficult to do work or hobbies that require them to see well up close (NHIS Adult Module) | Even when wearing glasses or contact lenses, because of your eyesight, how difficult is it for you…to do work or hobbies that require you to see well up close such as cooking, sewing, fixing things around the house, or using hand tools? | CLS, AVDF_CLS | 1999, 2002, 2008, 2016, 2017 | 2016, 2017 | 0 Not at all difficult 1 Only a little difficult 2 Somewhat difficult 3 Very difficult 4 Can’t do at all because of eyesight 6 Do not do this activity for other reasons 7 Refused 9 Don’t know |
| NHIS | Percentage of children who wear eyeglasses or contact lenses to read books, write, play hand-held games, or do other things that require them to see well up close (NHIS Child Module) | Does [fill: SC name] wear eyeglasses or contact lenses to read books, write, play hand-held games, or do other things that require [fill: her/him] to see well up close? | CVISREAD | 2008, 2016, 2017 | 2016, 2017 | 1 Yes 2 No 7 Refused 9 Don’t know |
VEHSS includes indicators of Night or Low Light Vision from self-report surveys.
Self-reported
Self-reported Night or Low Light Vision indicates the respondent replied that they have difficulty with tasks that require good night vision.
| Dataset | Description | Question text | Variable name(s) | Years available | Years analyzed | Response options |
|---|---|---|---|---|---|---|
| NHIS | Percentage of adults who even when wearing glasses or contact lenses find it (not at all, only a little, somewhat, or very) difficult to go down steps, stairs, or curbs in dim light or at night (NHIS Adult Module) | Even when wearing glasses or contact lenses, because of your eyesight, how difficult is it for you…to go down steps, stairs or curbs in dim light or at night? | NIT, AVDFNIT, AVDF_NIT | 1999, 2002, 2008, 2016, 2017 | 2016, 2017 | 0 Not at all difficult 1 Only a little difficult 2 Somewhat difficult 3 Very difficult 4 Can’t do at all (because of eyesight; 2008) 6 Do not do this activity (for other reasons; 2008) 7 Refused 8 Not ascertained (2008) 9 Don’t know |
Other Visual Disturbances includes indicators representing both Visual Function and Eye Health Conditions. VEHSS includes indicators of Other Visual Disturbances from claims databases and IRIS Registry.
Diagnosed or Treated
Other visual disturbances includes diagnosis codes indicating visual field defects, color vision deficiencies, night blindness, and other or unspecified visual disturbances.
- Diagnosed prevalence: IRIS Registry indicates Diagnosed conditions that exists in the patient’s medical record.
- Treated prevalence: Administrative claims databases indicate Treated conditions for which a diagnosis code was included anywhere on a submitted bill.
Diagnosed or Treated other visual disturbances includes a patient having one or more diagnosis codes indicating one or more of the other visual disturbances subgroups listed below.
| Subgroup | Indicated conditions |
|---|---|
| Visual field defect | Visual field defect includes diagnosis codes indicating defects of the visual field, including scotoma, sector or arcuate defects, localized visual field defects, homonymous bilateral field defects or contraction of the visual field. |
| Color blindness | Color blindness included diagnosis codes indicating color vision deficiencies. |
| Night blindness | Night blindness includes diagnosis codes indicating night blindness, abnormal dark adaptation and glare sensitivity. |
| Other/unspecified visual disturbances | Other/unspecified visual disturbances includes other disturbances or defects of sight including subjective visual disturbances, diplopia, other and unspecified disorders of binocular vision, and vision sensitivity deficiencies. |
Full lists of ICD9 and ICD10 codes: VEHSS diagnosis codes reportpdf iconexternal icon
| Dataset | Years analyzed | Measure type |
|---|---|---|
| IRIS | 2016, 2017, 2018 | Diagnosed |
| Medicare 100% FFS claims | 2014, 2015, 2016, 2017 | Treated |
| Managed Vision Care | 2016 | Treated |
| Medicaid MAX | 2013, 2014 | Treated |
| MarketScan commercial | 2016 | Treated |
Self-Assessed Blind or Difficulty Seeing includes self-response survey questions indicating blindness, difficulty seeing, or vision problems.
| Survey | Description | Question text | Variable name(s) | Years available | Years analyzed | Response options |
|---|---|---|---|---|---|---|
| ACS | Percentage of people who are blind or have serious difficulty seeing even when wearing glasses | Is this person blind or does he/she have serious difficulty seeing even when wearing glasses? | DIFFEYE | 2008-2016 | 2014-2015 | 1 Yes 2 No 0 Not applicable |
| NSCH | Percentage of children who were ever told by doctor that they had a vision problem that cannot be corrected with glasses or contact lenses | Does this child have any of the following? Blindness or problems with seeing, even when wearing glasses | BLINDNESS | 2016, 2017 | 2016, 2017 | 1 Yes 2 No |
| BRFSS | Percentage of people who are blind or have serious difficulty seeing even when wearing glasses | Are you blind or do you have serious difficulty seeing, even when wearing glasses? | BLIND | 2013-2017 | 2013-2017 | 1 Yes 2 No 7 Don’t know / Not sure 9 Refused |
| NHANES | Percentage of people blind in both eyes | “{Are you/Is SP} blind in both eyes? Next I have general questions about (your/SP’s) vision. With both eyes open, can (you/he/she) see light?” |
VIQ017 | 2005, 2008 | 2005, 2008 | 1 Yes 2 No 7 Don’t know / Not sure 9 Refused |
| NHIS | Percentage of adults who have trouble seeing even when wearing glasses or contact lenses (NHIS Adult Module) | Do you have any trouble seeing, even when wearing glasses or contact lenses? | AVISION | 1999-2017 | 2014-2015 | 1 Yes 2 No 7 Refused 8 Not ascertained 9 Don’t know |
| NHIS | Percentage of children have any trouble seeing even when wearing glasses or contact lenses (NHIS Child Module) | Does [child] have any trouble seeing [fill2:], even when wearing glasses or contact lenses? | CVISION | 1999-2017 | 2014-2015 | 1 Yes 2 No 7 Refused 8 Not ascertained 9 Don’t know |
| NHIS | Percentage of people who have (no, some, a lot) difficulty seeing even when wearing glasses (NHIS Functioning and Disability Module) | Do you have difficulty seeing, even when wearing glasses? | VIS_SS | 2011-2017 | 2014-2015 | 1 No difficulty 2 Some difficulty 3 A lot of difficulty 4 Cannot do at all/unable to do 7 Refused 9 Don’t know |
| NHIS | Percentage of adults who are blind or unable to see at all (NHIS Adult Module) | Are you blind or unable to see at all? | ABLIND | 1999-2017 | 2014-2015 | 1 Yes 2 No 7 Refused 9 Don’t know |
| NHIS | Percentage of children who are blind or unable to see at all (NHIS Child Module) | Is [child] blind or unable to see at all? | CBLIND | 1999-2017 | 2014-2015 | 1 Yes 2 No 7 Refused 8 Not ascertained 9 Don’t know |
VEHSS includes indicators of Visual Field from self-report surveys.
Self-reported
Self-reported Far-Distance Visual Function indicates the respondent replied that they have difficulty with tasks that require good peripheral vision.
| Dataset | Description | Question text | Variable name(s) | Years available | Years analyzed | Response options |
|---|---|---|---|---|---|---|
| NHIS | Percentage of adults who even when wearing glasses or contact lenses find it (not at all, only a little, somewhat, or very) difficult to notice objects off to the side while you are walking along (NHIS Adult Module) | Even when wearing glasses or contact lenses, because of your eyesight, how difficult is it for you…to notice objects off to the side while you are walking along? | PER, AVDFPER, AVDF_PER | 1999, 2002, 2008, 2016, 2017 |
2016, 2017 | 0 Not at all difficult 1 Only a little difficult 2 Somewhat difficult 3 Very difficult 4 Can’t do at all (because of eyesight; 2008) 6 Do not do this activity (for other reasons; 2008) 7 Refused 8 Not ascertained (2008) 9 Don’t know |