Hayden Christensen was 23 in Star Wars: Episode III - Revenge of the Sith when he played the character 'Anakin Skywalker / Darth Vader'.
That was over 19 years ago in 2005.
Today he is 43, and has starred in 35 movies in total, 18 of those since Star Wars: Episode III - Revenge of the Sith was released.
In Star Wars: Episode III - Revenge of the Sith, I think Hayden Christensen looks: