In a medium saucepan, combine 1 cup of water and the sugar over medium heat, stirring until the sugar completely dissolves. Remove from heat and let cool to room temperature.
In a blender, add the fresh blueberries and lemon juice, blending until smooth.
Strain the blueberry mixture through a fine mesh sieve into a mixing bowl or pitcher to remove the skins and seeds, pressing gently with a spoon to extract as much liquid as possible.
Add the cooled simple syrup (from Step 1) to the blueberry juice, along with the remaining 1 cup of water, lemon zest, and a pinch of salt. Stir until well combined.
Pour the mixture into popsicle molds, leaving a little space at the top for expansion.
Insert popsicle sticks and freeze for at least 6 hours, or until completely solid.
To release the popsicles, run warm water over the outside of the molds for a few seconds and gently pull out the popsicles.
Notes
Serve the popsicles on a wooden tray with fresh mint leaves sprinkled around them for an attractive and refreshing display.