Preheat the oven to 350°F. Lightly greased muffin tins or line tins with cupcake papers.
In a large mixing bowl, combine the flour, baking powder, baking soda, and salt. Set aside.
In a medium mixing bowl, cream the butter and sugar until thoroughly blended. Beat in the eggs, one egg at a time. Add lemon juice, lemon zest, and vanilla until smooth in consistency. Beat in flour mixture and buttermilk, alternating dry ingredients with buttermilk, adding about 1/3 each time. The mixture should be smooth and creamy. Fold in the blueberries and mix until the blueberries are even distributed throughout the batter.
Pour the batter into the muffin tins, filling the tins about half full, Bake until the muffin tops are golden, 20 - 25 minutes. Allow to cool about 5 minutes.
In a small mixing bowl, combine the sugar, lemon juice, and lemon zest until a smooth consistency is achieved. Apply to the muffin tops while still warm.