Combine the sugar and 1 cup of water in a saucepan over medium heat. 

Stir until the sugar has dissolved. 

Add the blueberries and bring to boil. 

Reduce the heat and simmer for 5 minutes. 

Strain the mixture through fine sieve. 

In a pitcher combine the lemon juice and remaining water. 

Add the blueberry syrup and stir to combine. 

Pour the lemonade into the glasses filled with ice and serve.