Meanwhile, in 1-quart saucepan, mix sugar, cornstarch and water. Stir in 1/2 cup of the blueberries. Heat to boiling; reduce heat to medium-low. Cook about 5 minutes or until slightly thickened. Stir in lemon juice; remove from heat. Cool 10 minutes. Stir in remaining 1 cup blueberries. Cover; refrigerate until chilled, at least 1 hour.