Cut lemons crosswise into paper-thin rounds using a mandoline or a very sharp knife; discard ends and seeds. Place lemon slices in a medium nonreactive bowl, and add sugar; toss to coat. Cover with plastic wrap, and let stand at room temperature overnight.

Roll out dough on a lightly floured work surface to 1/8 inch thick. Cut dough into seven 6-inch rounds. Fit rounds into 4 1/2-inch round tart pans with removable bottoms. Trim edges flush with tops. Place on a rimmed baking sheet; freeze until firm, 30 minutes or overnight.

Preheat oven to 450 degrees, with rack in lower third. Add eggs to lemon mixture, and stir to combine. Pour through a fine sieve into a medium bowl. Divide liquid among tart shells, then top with the lemon slices, arranging decoratively.

Bake tarts on baking sheet 15 minutes. Reduce heat to 350 degrees, bake until filling is set and beginning to brown, about 15 minutes. Let cool on sheet on a wire rack 10 minutes. Remove tarts from pans, and let cool completely on wire racks.