In a small saucepan, add 1 cup of water, sugar, and blueberries. Cook over medium-low heat until the sugar melts and the blueberries start to break down--about 5 to 7 minutes. While cooking, smash the blueberries with the back of a sauce spoon to release all of the juices. Note: Taste the blueberry syrup and adjust the sweetness to taste. Keeping in mind the blueberries are naturally sweet.
Over a small bowl, strain the blueberry syrup through a fine mesh strainer--pushing the blueberries through the strainer with the back of a sauce spoon. Set aside to cool.
Add the blueberry simple syrup, lemon juice and 4 cups of water to your pitcher. Add more water to dilute the lemonade more if you prefer. Chill and serve over ice with extra blueberries and a slice of lemon.