Left Lens prescription using the parameters element

{
  "resourceType" : "DeviceRequest",
  "id" : "left-lens",
  "identifier" : [{
    "system" : "http://www.happysight.com/prescription",
    "value" : "15013L"
  }],
  "groupIdentifier" : {
    "system" : "http://acme.org",
    "value" : "15013"
  },
  "status" : "completed",
  "intent" : "original-order",
  "code" : {
    "concept" : {
      "coding" : [{
        "system" : "http://terminology.hl7.org/CodeSystem/ex-visionprescriptionproduct",
        "code" : "lens"
      }]
    }
  },
  "parameter" : [{
    "code" : {
      "coding" : [{
        "system" : "http://loinc.org",
        "code" : "28842-3",
        "display" : "Left glasses lens prescription Sphere far"
      }],
      "text" : "sphere, left lens"
    },
    "valueQuantity" : {
      "value" : -1.00,
      "unit" : "Diopter",
      "system" : "http://unitsofmeasure.org",
      "code" : "[diop]"
    }
  },
  {
    "code" : {
      "coding" : [{
        "system" : "http://loinc.org",
        "code" : "28843-1",
        "display" : "Left glasses lens prescription Cylinder far"
      }],
      "text" : "cylinder, left lens"
    },
    "valueQuantity" : {
      "value" : -0.50,
      "unit" : "Diopter",
      "system" : "http://unitsofmeasure.org",
      "code" : "[diop]"
    }
  },
  {
    "code" : {
      "coding" : [{
        "system" : "http://loinc.org",
        "code" : "28844-9",
        "display" : "Left glasses lens prescription Axis far"
      }],
      "text" : "axis, left lens"
    },
    "valueQuantity" : {
      "value" : 180,
      "unit" : "Degrees",
      "system" : "http://unitsofmeasure.org",
      "code" : "deg"
    }
  }],
  "subject" : {
    "reference" : "Patient/example"
  },
  "occurrenceDateTime" : "2014-06-15",
  "requester" : {
    "reference" : "Practitioner/example"
  }
}