AL PACINO GOOD GENES OR GOOD DOCS?

4/26/2015 12:30 AM PDT

When it comes to good looks ... Al Pacino is anything but a "Scarface."

Here's a 39-year-old version of the "Michael Corleone" stud at a celebrity benefit back in 1979 (left) and 36 years later ... the godfather of cool -- who is celebrating his 75th birthday this weekend -- at a NYC movie theater last month (right).

Hoo-ah!

The question is ...