Combine half and half and sugar in a saucepan; bring to a simmer over low heat.
Cook and stir until sugar is dissolved.
Add 1/4 cup of the hot half & half mixture into the eggs, stirring constantly to temper the eggs.
Add another 1/4 cup of the half & half mixture, and then pour the egg mixture back into the saucepan.
Cook and stir over low heat until the mixture just coats the back of a metal spoon.
Strain custard mixture through a sieve.
Add, lemon juice, zest and vanilla, stir.
Pour the mixture into ice cream maker and freeze according to machines directions.
Crush 1/4 cup lemon drop candies.
Add to ice cream.
Transfer ice cream to a lidded freezer container, and freeze for 3 hours or until firm.