Separate egg yolks and blend together in a large mixing bowl. Blend thoroughly. Add condensed milk to egg yolks and blend with wire whisk until both are mixed together well. Finally, add real lemon juice and once again mix ingredients together until you get one smooth product.
Pour evenly into two graham cracker pie shells.
Bake at 375 degrees F for 50 minutes or until center does not jiggle. Remove from oven and let cool for 1 hour on the counter. Must refrigerate overnight. Top with Cool Whip. Serve cold.