Using VisionPrescription prism fields

We are developing an application for the optical industry. In the VisionPrescription data packet, it appears as though only one prism value and direction can be sent, but for many patients, two prism values may be required (one for up/down, and another for in/out). Is there a way to send multiple prism values for each eye of a prescription? Thanks in advance!

The VisionPrescription resource has a very low maturity rating. It was developed by the financial community and we’ve been waiting for some domain experts to review it. For now, you will need to use extensions for any needed data elements it doesn’t provide, but feedback on what’s actually needed in the vision community would be appreciated. (We’re evaluating deprecating the resource in R4 and replacing it with a profile on the revised DeviceRequest resource which supports providing multiple parameter values (the explicit vision parameters would become name-value pairs with codes for things like eye, sphere, cylinder, etc.). You can provide feedback by using the “propose a change” link at the bottom of any page in the spec. You’ll need to register the first time, but that’s free.

The VisionPrescription has been developed to convey the standard vision prescription information for lens and contacts used through the world. We will amend the VisionPrescription to handle two prism settings for each eye, however if you are using R3 (FHIR 3.0) an extension would be required to contain the second prism and base pair, for example:

<dispense> 
  <extension url="url="http://hl7.org/fhir/StructureDefinition/visionprescription-prism">
    <extension url="prism" >
	<valueDecimal value="0.1"/>
    </extension>
    <extension url="base" >
	<valueCode value="in"/>
    </extension>
  </extension>
  <product> 
    <coding> 
	<system value="http://hl7.org/fhir/ex-visionprescriptionproduct"/> 
	<code value="lens"/> 
    </coding> 
  </product> 
  <eye value="right"/> 
  <sphere value="-2.00"/> 
  <prism value="0.5"/> 
  <base value="down"/> 
  <add value="2.00"/> 
</dispense> 

Thank you! Your explanation and suggestions are a great help. I will also provide feedback using the propose a change link.