Serve this light parfait in juice glasses at your next brunch gathering.
Set aside 1/2 cup blueberries for garnish. Put remaining blueberries and 1/4 cup sugar in a medium saucepan. Cover; cook over medium heat 5 minutes. Uncover; cook, tossing occasionally, until berries begin to darken, 2 to 3 minutes. Bring to a boil; cook 1 minute more. Pour into a medium nonreactive bowl (glass or ceramic); let cool completely.
Put yogurt, remaining 1/4 cup sugar, and the lemon juice in a medium bowl. Set aside 1/2 teaspoon lemon zest for garnish. Very finely chop remaining 1 1/2 teaspoons lemon zest, then stir into yogurt. Set yogurt aside.
Divide blueberry sauce evenly among six juice glasses. Divide yogurt among glasses, and spoon over sauce. Sprinkle parfaits with reserved berries and zest. If not serving immediately, refrigerate, covered with plastic wrap, for up to 3 hours.
You can prepare the blueberry sauce and the lemony yogurt up to two days ahead, and refrigerate both in airtight containers.