SET @json_t = '{
  "REyeLens": {
    "Sph": "",
    "Cyl": "",
    "Axis": "",
    "LongPd": "11",
    "Add": "",
    "ShortPd": "",
    "BaseIo": "/",
    "BaseUd": "/",
    "BareEye": "",
    "Adjust": ""
  },
  "LEyeLens": {
    "Sph": "",
    "Cyl": "",
    "Axis": "",
    "LongPd": "11",
    "Add": "",
    "ShortPd": "",
    "BaseIo": "/",
    "BaseUd": "/",
    "BareEye": "",
    "Adjust": ""
  },
  "RContLens": {
    "Sph": "",
    "Cyl": "",
    "Axis": "",
    "Add": "",
    "Bc": "",
    "Dia": "",
    "Kerato": "",
    "Prescript": "",
    "Adjust": ""
  },
  "LContLens": {
    "Sph": "",
    "Cyl": "",
    "Axis": "",
    "Add": "",
    "Bc": "",
    "Dia": "",
    "Kerato": "",
    "Prescript": "",
    "Adjust": ""
  },
  "Symptoms": "",
  "OldREyeLens": {
    "Sph": "",
    "Cyl": "",
    "Axis": "",
    "LongPd": "",
    "Add": "",
    "ShortPd": "",
    "BaseIo": "/",
    "BaseUd": "/",
    "BareEye": "",
    "Adjust": ""
  },
  "OldLEyeLens": {
    "Sph": "",
    "Cyl": "",
    "Axis": "",
    "LongPd": "",
    "Add": "",
    "ShortPd": "",
    "BaseIo": "/",
    "BaseUd": "/",
    "BareEye": "",
    "Adjust": ""
  },
  "CcREyeLens": {
    "Sph": "",
    "Cyl": "",
    "Axis": "",
    "LongPd": "",
    "Add": "",
    "ShortPd": "",
    "BaseIo": "/",
    "BaseUd": "/",
    "BareEye": "",
    "Adjust": ""
  },
  "CcLEyeLens": {
    "Sph": "",
    "Cyl": "",
    "Axis": "",
    "LongPd": "",
    "Add": "",
    "ShortPd": "",
    "BaseIo": "/",
    "BaseUd": "/",
    "BareEye": "",
    "Adjust": ""
  },
  "FixEye": 0,
  "Stereosia": 0,
  "ColorVision": 0,
  "OdImGrid": 0,
  "OsImGrid": 0,
  "Screen": {
    "Shielding": {
      "Long": "",
      "Short": ""
    },
    "FourDot": {
      "Long": 0,
      "Short": 0,
      "LongStr": "",
      "ShortStr": ""
    },
    "Converge": {
      "Normal": 0,
      "Str": ""
    },
    "Near": {
      "OdStr": "",
      "OsStr": ""
    },
    "Easy": {
      "OuStr": "",
      "OdStr": "",
      "OsStr": ""
    }
  },
  "BroadH": {
    "X": "[]",
    "Y": "[]",
    "Drage": "[]"
  },
  "Bincular": {
    "Location": {
      "LongHori": "",
      "LongVert": "",
      "ShortHori": "",
      "ShortVert": ""
    },
    "Relative": {
      "Pra": "",
      "Nra": ""
    },
    "Lag": 0,
    "Aca": "",
    "Fusion": {
      "LongBo": {
        "Clo": "",
        "Dis": "",
        "Rec": ""
      },
      "LongBi": {
        "Clo": "",
        "Dis": "",
        "Rec": ""
      },
      "LongOdBd": {
        "Dis": "",
        "Rec": ""
      },
      "LongOdBu": {
        "Dis": "",
        "Rec": ""
      },
      "LongOsBd": {
        "Dis": "",
        "Rec": ""
      },
      "LongOsBu": {
        "Dis": "",
        "Rec": ""
      },
      "ShortBo": {
        "Clo": "",
        "Dis": "",
        "Rec": ""
      },
      "ShortBi": {
        "Clo": "",
        "Dis": "",
        "Rec": ""
      },
      "ShortOdBd": {
        "Dis": "",
        "Rec": ""
      },
      "ShortOdBu": {
        "Dis": "",
        "Rec": ""
      },
      "ShortOsBd": {
        "Dis": "",
        "Rec": ""
      },
      "ShortOsBu": {
        "Dis": "",
        "Rec": ""
      }
    }
  },
  "Pameter": {
    "Oh": {
      "R": "",
      "L": ""
    },
    "Pd": {
      "R": "",
      "L": ""
    },
    "Distance": {
      "R": "",
      "L": ""
    },
    "Inset": {
      "R": "",
      "L": ""
    },
    "Face": "",
    "Tilt": "",
    "Length": ""
  },
  "Payment": {
    "CardCompany": "",
    "CashReceipt": "",
    "GiftCard": ""
  }
}';

SELECT json_extract(@json_t, '$.REyeLens.LongPd');