1. Mix cornstarch, 1 cup sugar, and salt in a heavy saucepan. Add a small amount of the orange juice and blend until smooth. Stir in remaining orange juice.
2. Bring mixture to boiling, stirring constantly, and cook 3 to 5 minutes.
3. Stir about 3 tablespoons of the hot mixture into beaten eggs; immediately blend with mixture in saucepan.
4. Cook and stir about 3 minutes. Remove from water and cool. Stir in lemon peel. Chill.
5. Meanwhile, sprinkle 2 tablespoons sugar over blue berries and allow to stand at least 30 minutes. Spoon alternating layers of custard and blueberries in parfait glasses, beginning with a layer of custard and ending with blueberries. Top with whipped cream, if desired.