Wash and spin dry lettuce, breaking larger leaves into 4 inch pieces. Add pear to blender along with rice vinegar, to prevent pear from browning. Add the sugar, salt, pepper, and hazelnut oil and puree until smooth. Place the cleaned, torn lettuce in a bowl. Arrange the dressed lettuce on chilled plates. Slice each pear in half and spoon out the cores. Lay the halves on a cutting board, flat side down, and slice each half on a bias into 7 or 8 even slices. Press the sliced pear halves lightly to fan them out and carefully transfer the pear fan to the lettuce. Scatter hazelnuts and crumbled blue cheese over each salad and serve.