In a small or medium saucepan, bring lemon juice and blueberries to a boil. Stir occasionally. When your mixture begins boiling, cook for 4 minutes stirring frequently. Remove from heat.
Over a large bowl, pour blueberry mixture into a large mesh strainer. Rinse out saucepan and set aside, you will be reusing this pan. Take a spoon, smeer and mash the blueberries that remain in the strainer. Continue this process until you have squeesed out as much juice as can come out. Discard solids. Set aside blueberry lemon juice.
Add 4 cups water to saucepan. Bring to a boil. Remove from heat and toss in tea bags. Cover and let sit for 5 minutes. Discard tea bags after shaking to remove any remaining liquid. Add sugar, stir until dissolved. Pour blueberry lemon mixture into iced tea. Give a quick stir and carefully transfer to a serving pitcher. Use a funnel, if necessary, to prevent spilling. I find sometimes even with the funnel I have issues but it definitely helps! Transfer to fridge for a minimum of an hour. Best served over ice.