In a saucepan, heat the blueberries and 1/4 cup of the sugar over medium heat, stirring occasionally, until the berries pop and begin to cook down, about 10 minutes. Set aside to cool, then refrigerate until ready to use.
In a saucepan, heat the cream, half-and-half, and vanilla bean over medium heat, stirring occasionally to make sure the mixture does not scorch on the bottom. When it reaches a fast simmer (do not let it boil), turn off the heat and set aside to infuse 10 to 15 minutes.
In a medium bowl, whisk together the egg yolks and the remaining 3/4 cup sugar. Whisking constantly, slowly pour the still-hot cream mixture into the egg yolk mixture. Return the mixture to the saucepan and cook over medium heat, stirring constantly with a wooden spoon. At 160 degrees F, the mixture will give off a puff of steam. When the mixture reaches 180 degrees F, it will be thickened and creamy, like eggnog. If you do not have a thermometer, test it by dipping a wooden spoon into the mixture. Run your finger down the back of the spoon. If the stripe remains clear, the mixture is ready; if the edges blur, the mixture is not quite thick enough yet. When it is ready, quickly remove it from the heat.
Meanwhile, half-fill a large bowl with ice water. Strain the mixture into a smaller bowl to smooth it and remove the vanilla bean. Whisk in the orange zest. Rest the smaller bowl in the ice water and let the mixture cool, stirring often, then continue according to the directions of your ice cream maker.
Put a large mixing bowl in the freezer to chill. When the ice cream is finished, transfer it to the frozen bowl. Using a sturdy rubber spatula, fold in the blueberry mixture until swirled. Freeze.
Recipe courtesy of Gale Gand