Preheat the oven to 325 degrees.with the rack in the center. Butter a 10-inch tube pan; set aside. In the bowl of an electric mixer fitted with the paddle attachment, cream butter and sugar on medium speed until light and fluffy, about 3 minutes. Add eggs, one at a time, beating well after each addition, and scraping down the sides of the bowl.
Sift together flour, baking soda, and salt into a medium bowl. Add the flour mixture to the butter mixture in three additions, alternating with buttermilk, and beginning and ending with the flour mixture. Stir in lemon zest and juice. Gently fold in blueberries.
Pour batter into prepared pan, smoothing the top with a rubber spatula. Bake until a tester inserted into the center comes out clean and the cake has begun to pull away from the sides of the pan, about 1 hour and 15 minutes. Transfer the pan to a wire rack to cool for 10 minutes.
Meanwhile, prepare the glaze: In a small bowl, whisk together confectioners' sugar, lemon juice, and lemon zest until smooth; set aside.
Invert the cake onto a rack. Prick the surface numerous times with a toothpick. Brush the glaze over the surface of the warm cake, and cool to room temperature. Store wrapped in plastic for up to 2 days at room temperature.