Eyematics Core Data Set - Local Development build (v2025.0.0-alpha) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions
Extension: LensDuringVATestSpecification
| Official URL: https://eyematics.org/fhir/eyematics-kds/StructureDefinition/LensDuringVATestSpecification | Version: 2025.0.0-alpha | |||
| Draft as of 2025-10-18 | Computable Name: LensDuringVATestSpecification | |||
Specification any Lens that was n front of an eye during a Visual Acuity test test
Context of Use
-
Element ID:
Observation.component.extension
This extension may be used on the following element(s)
Usage info
Usages:
- Use this Extension: Visual Acuity (VA)
You can also check for usages in the FHIR IG Statistics
Formal Views of Extension Content
Description of Profiles, Differentials, Snapshots, and how the XML and JSON presentations work.
This structure is derived from Extension
| Name | Flags | Card. | Type | Description & Constraints Filter:   |
|---|---|---|---|---|
  Extension |
0..* | Extension | Extension | |
  Slices for extension |
1..* | Extension | Extension Slice: Unordered, Open by value:url | |
   extension:BasedOn |
0..* | Extension | Where the Lens Data comes fro | |
  extension |
0..0 | |||
| url |
1..1 | uri | "BasedOn" | |
  value[x] |
0..1 | Reference() | Where the Lens Data is coming from | |
| extension:type |
1..1 | Extension | Lens Type (Contact,Spectracle or Trial) | |
| extension |
0..0 | |||
| url |
1..1 | uri | "type" | |
 value[x] |
0..1 | CodeableConcept | Value of extension Binding: VA Lens Types (preferred) | |
| extension:sphere |
0..1 | Extension | Power of the lens | |
| extension |
0..0 | |||
| url |
1..1 | uri | "sphere" | |
 value[x] |
0..1 | decimal | Value of extension | |
| extension:cylinder |
0..1 | Extension | Lens power for astigmatism | |
| extension |
0..0 | |||
| url |
1..1 | uri | "cylinder" | |
  value[x] |
0..1 | Value of extension | ||
  valueDecimal |
decimal | |||
 valueQuantity |
Quantity | |||
| extension:axis |
0..1 | Extension | Lens meridian which contain no power for astigmatism | |
| extension |
0..0 | |||
| url |
1..1 | uri | "axis" | |
| value[x] |
0..1 | integer | Value of extension | |
| extension:PrismAmount |
0..1 | Extension | Amount of adjustment | |
| extension |
0..0 | |||
| url |
1..1 | uri | "PrismAmount" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:PrismBaseDirection |
0..1 | Extension | The relative base, or reference lens edge, for the prism. | |
| extension |
0..0 | |||
| url |
1..1 | uri | "PrismBaseDirection" | |
| value[x] |
0..1 | CodeableConcept | Value of extension | |
| extension:add |
0..* | Extension | Added power for multifocal levels | |
| extension |
0..0 | |||
| url |
1..1 | uri | "add" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:power |
0..1 | Extension | Contact lens power | |
| extension |
0..0 | |||
| url |
1..1 | uri | "power" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:backCurve |
0..1 | Extension | Contact lens back curvature | |
| extension |
0..0 | |||
| url |
1..1 | uri | "backCurve" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:diameter |
0..1 | Extension | Contact lens diameter | |
| extension |
0..0 | |||
| url |
1..1 | uri | "diameter" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:duration |
0..1 | Extension | Lens wear duration | |
| extension |
0..0 | |||
| url |
1..1 | uri | "duration" | |
| value[x] |
0..1 | Quantity | Value of extension | |
| extension:color |
0..* | Extension | Extension | |
| extension |
0..0 | |||
| url |
1..1 | uri | "color" | |
| value[x] |
0..1 | string | Value of extension | |
| extension:brand |
0..* | Extension | Extension | |
| extension |
0..0 | |||
| url |
1..1 | uri | "brand" | |
| value[x] |
0..1 | string | Value of extension | |
 extension:note |
0..* | Extension | Extension | |
| extension |
0..0 | |||
| url |
1..1 | uri | "note" | |
| value[x] |
0..1 | string | Value of extension | |
| url |
1..1 | uri | "https://eyematics.org/fhir/eyematics-kds/StructureDefinition/LensDuringVATestSpecification" | |
| value[x] |
0..0 | |||
| Documentation for this format | ||||
| Name | Flags | Card. | Type | Description & Constraints Filter: |
|---|---|---|---|---|
| Extension |
0..* | Extension | Extension | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| Slices for extension |
1..* | Extension | Extension Slice: Unordered, Open by value:url | |
| extension:BasedOn |
0..* | Extension | Where the Lens Data comes fro | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "BasedOn" | |
| value[x] |
0..1 | Reference() | Where the Lens Data is coming from | |
| extension:type |
1..1 | Extension | Lens Type (Contact,Spectracle or Trial) | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "type" | |
| value[x] |
0..1 | CodeableConcept | Value of extension Binding: VA Lens Types (preferred) | |
| extension:sphere |
0..1 | Extension | Power of the lens | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "sphere" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:cylinder |
0..1 | Extension | Lens power for astigmatism | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "cylinder" | |
| value[x] |
0..1 | Value of extension | ||
| valueDecimal |
decimal | |||
| valueQuantity |
Quantity | |||
| extension:axis |
0..1 | Extension | Lens meridian which contain no power for astigmatism | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "axis" | |
| value[x] |
0..1 | integer | Value of extension | |
| extension:PrismAmount |
0..1 | Extension | Amount of adjustment | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "PrismAmount" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:PrismBaseDirection |
0..1 | Extension | The relative base, or reference lens edge, for the prism. | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "PrismBaseDirection" | |
| value[x] |
0..1 | CodeableConcept | Value of extension | |
| extension:add |
0..* | Extension | Added power for multifocal levels | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "add" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:power |
0..1 | Extension | Contact lens power | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "power" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:backCurve |
0..1 | Extension | Contact lens back curvature | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "backCurve" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:diameter |
0..1 | Extension | Contact lens diameter | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "diameter" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:duration |
0..1 | Extension | Lens wear duration | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "duration" | |
| value[x] |
0..1 | Quantity | Value of extension | |
| extension:color |
0..* | Extension | Extension | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "color" | |
| value[x] |
0..1 | string | Value of extension | |
| extension:brand |
0..* | Extension | Extension | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "brand" | |
| value[x] |
0..1 | string | Value of extension | |
| extension:note |
0..* | Extension | Extension | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "note" | |
| value[x] |
0..1 | string | Value of extension | |
| url |
1..1 | uri | "https://eyematics.org/fhir/eyematics-kds/StructureDefinition/LensDuringVATestSpecification" | |
| Documentation for this format | ||||
This structure is derived from Extension
Summary
Complex Extension: Specification any Lens that was n front of an eye during a Visual Acuity test test
- BasedOn: Reference: Lens Data may originate from Corrective Device Resource of Glasses or Contacts, or from Lensmeter Measurement, of from manual input.
- type: CodeableConcept: This identifies whether the lens is a contact lens, a lens in spectacles or a trial lens (which may or may not be inside a phoropter)
- sphere: decimal: Lens power measured in dioptres (0.25 units)
- cylinder: decimal, Quantity: Power adjustment for astigmatism measured in dioptres (0.25 units).
- axis: integer: Adjustment for astigmatism measured in integer degrees.
- PrismAmount: decimal: Amount of prism to compensate for eye alignment in fractional units.
- PrismBaseDirection: CodeableConcept: The relative base, or reference lens edge, for the prism.
- add: decimal: Power adjustment for multifocal lenses measured in dioptres (0.25 units).
- power: decimal: Contact lens power measured in dioptres (0.25 units).
- backCurve: decimal: Back curvature measured in millimetres.
- diameter: decimal: Contact lens diameter measured in millimetres.
- duration: Quantity: n The recommended maximum wear period for the lens.
- color: string: An Extension
- brand: string: An Extension
- note: string: An Extension
Differential View
This structure is derived from Extension
| Name | Flags | Card. | Type | Description & Constraints Filter: |
|---|---|---|---|---|
| Extension |
0..* | Extension | Extension | |
| Slices for extension |
1..* | Extension | Extension Slice: Unordered, Open by value:url | |
| extension:BasedOn |
0..* | Extension | Where the Lens Data comes fro | |
| extension |
0..0 | |||
| url |
1..1 | uri | "BasedOn" | |
| value[x] |
0..1 | Reference() | Where the Lens Data is coming from | |
| extension:type |
1..1 | Extension | Lens Type (Contact,Spectracle or Trial) | |
| extension |
0..0 | |||
| url |
1..1 | uri | "type" | |
| value[x] |
0..1 | CodeableConcept | Value of extension Binding: VA Lens Types (preferred) | |
| extension:sphere |
0..1 | Extension | Power of the lens | |
| extension |
0..0 | |||
| url |
1..1 | uri | "sphere" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:cylinder |
0..1 | Extension | Lens power for astigmatism | |
| extension |
0..0 | |||
| url |
1..1 | uri | "cylinder" | |
| value[x] |
0..1 | Value of extension | ||
| valueDecimal |
decimal | |||
| valueQuantity |
Quantity | |||
| extension:axis |
0..1 | Extension | Lens meridian which contain no power for astigmatism | |
| extension |
0..0 | |||
| url |
1..1 | uri | "axis" | |
| value[x] |
0..1 | integer | Value of extension | |
| extension:PrismAmount |
0..1 | Extension | Amount of adjustment | |
| extension |
0..0 | |||
| url |
1..1 | uri | "PrismAmount" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:PrismBaseDirection |
0..1 | Extension | The relative base, or reference lens edge, for the prism. | |
| extension |
0..0 | |||
| url |
1..1 | uri | "PrismBaseDirection" | |
| value[x] |
0..1 | CodeableConcept | Value of extension | |
| extension:add |
0..* | Extension | Added power for multifocal levels | |
| extension |
0..0 | |||
| url |
1..1 | uri | "add" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:power |
0..1 | Extension | Contact lens power | |
| extension |
0..0 | |||
| url |
1..1 | uri | "power" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:backCurve |
0..1 | Extension | Contact lens back curvature | |
| extension |
0..0 | |||
| url |
1..1 | uri | "backCurve" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:diameter |
0..1 | Extension | Contact lens diameter | |
| extension |
0..0 | |||
| url |
1..1 | uri | "diameter" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:duration |
0..1 | Extension | Lens wear duration | |
| extension |
0..0 | |||
| url |
1..1 | uri | "duration" | |
| value[x] |
0..1 | Quantity | Value of extension | |
| extension:color |
0..* | Extension | Extension | |
| extension |
0..0 | |||
| url |
1..1 | uri | "color" | |
| value[x] |
0..1 | string | Value of extension | |
| extension:brand |
0..* | Extension | Extension | |
| extension |
0..0 | |||
| url |
1..1 | uri | "brand" | |
| value[x] |
0..1 | string | Value of extension | |
| extension:note |
0..* | Extension | Extension | |
| extension |
0..0 | |||
| url |
1..1 | uri | "note" | |
| value[x] |
0..1 | string | Value of extension | |
| url |
1..1 | uri | "https://eyematics.org/fhir/eyematics-kds/StructureDefinition/LensDuringVATestSpecification" | |
| value[x] |
0..0 | |||
| Documentation for this format | ||||
Snapshot View
| Name | Flags | Card. | Type | Description & Constraints Filter: |
|---|---|---|---|---|
| Extension |
0..* | Extension | Extension | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| Slices for extension |
1..* | Extension | Extension Slice: Unordered, Open by value:url | |
| extension:BasedOn |
0..* | Extension | Where the Lens Data comes fro | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "BasedOn" | |
| value[x] |
0..1 | Reference() | Where the Lens Data is coming from | |
| extension:type |
1..1 | Extension | Lens Type (Contact,Spectracle or Trial) | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "type" | |
| value[x] |
0..1 | CodeableConcept | Value of extension Binding: VA Lens Types (preferred) | |
| extension:sphere |
0..1 | Extension | Power of the lens | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "sphere" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:cylinder |
0..1 | Extension | Lens power for astigmatism | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "cylinder" | |
| value[x] |
0..1 | Value of extension | ||
| valueDecimal |
decimal | |||
| valueQuantity |
Quantity | |||
| extension:axis |
0..1 | Extension | Lens meridian which contain no power for astigmatism | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "axis" | |
| value[x] |
0..1 | integer | Value of extension | |
| extension:PrismAmount |
0..1 | Extension | Amount of adjustment | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "PrismAmount" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:PrismBaseDirection |
0..1 | Extension | The relative base, or reference lens edge, for the prism. | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "PrismBaseDirection" | |
| value[x] |
0..1 | CodeableConcept | Value of extension | |
| extension:add |
0..* | Extension | Added power for multifocal levels | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "add" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:power |
0..1 | Extension | Contact lens power | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "power" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:backCurve |
0..1 | Extension | Contact lens back curvature | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "backCurve" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:diameter |
0..1 | Extension | Contact lens diameter | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "diameter" | |
| value[x] |
0..1 | decimal | Value of extension | |
| extension:duration |
0..1 | Extension | Lens wear duration | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "duration" | |
| value[x] |
0..1 | Quantity | Value of extension | |
| extension:color |
0..* | Extension | Extension | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "color" | |
| value[x] |
0..1 | string | Value of extension | |
| extension:brand |
0..* | Extension | Extension | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "brand" | |
| value[x] |
0..1 | string | Value of extension | |
| extension:note |
0..* | Extension | Extension | |
| id |
0..1 | string | Unique id for inter-element referencing | |
| extension |
0..0 | |||
| url |
1..1 | uri | "note" | |
| value[x] |
0..1 | string | Value of extension | |
| url |
1..1 | uri | "https://eyematics.org/fhir/eyematics-kds/StructureDefinition/LensDuringVATestSpecification" | |
| Documentation for this format | ||||
This structure is derived from Extension
Summary
Complex Extension: Specification any Lens that was n front of an eye during a Visual Acuity test test
- BasedOn: Reference: Lens Data may originate from Corrective Device Resource of Glasses or Contacts, or from Lensmeter Measurement, of from manual input.
- type: CodeableConcept: This identifies whether the lens is a contact lens, a lens in spectacles or a trial lens (which may or may not be inside a phoropter)
- sphere: decimal: Lens power measured in dioptres (0.25 units)
- cylinder: decimal, Quantity: Power adjustment for astigmatism measured in dioptres (0.25 units).
- axis: integer: Adjustment for astigmatism measured in integer degrees.
- PrismAmount: decimal: Amount of prism to compensate for eye alignment in fractional units.
- PrismBaseDirection: CodeableConcept: The relative base, or reference lens edge, for the prism.
- add: decimal: Power adjustment for multifocal lenses measured in dioptres (0.25 units).
- power: decimal: Contact lens power measured in dioptres (0.25 units).
- backCurve: decimal: Back curvature measured in millimetres.
- diameter: decimal: Contact lens diameter measured in millimetres.
- duration: Quantity: n The recommended maximum wear period for the lens.
- color: string: An Extension
- brand: string: An Extension
- note: string: An Extension
Other representations of profile: CSV, Excel, Schematron
Terminology Bindings
| Path | Status | Usage | ValueSet | Version | Source |
| Extension.extension:type.value[x] | Base | preferred | VA Lens Types | 📦2025.0.0-alpha | This IG |
Constraints
| Id | Grade | Path(s) | Description | Expression |
| ele-1 | error | **ALL** elements | All FHIR elements must have a @value or children |
hasValue() or (children().count() > id.count())
|
| ext-1 | error | **ALL** extensions | Must have either extensions or value[x], not both |
extension.exists() != value.exists()
|