In a large mixer bowl, beat cheese until fluffy. Gradually beat in sweetened condensed milk until smooth. Stir in 1/2 cup lemon juice and vanilla.
Pour into prepared crust.
In medium saucepan, combine sugar and cornstarch, mix well. Add water and remaining two tablespoons of lemon juice and then blueberries. Bring to boil.
Reduce heat and simmer 3 minutes or until thick and clear.
Cool ten minutes. Spread over pie. Chill three hours or until set.
Makes one 9 inch pie. Refrigerate leftovers