After Optimeyes, I tried to look for face recognition software on the net, until I arrived here:
http://new-mozart.dis.ulpgc.es/encara2Supposedly it can identify gender. Really. Let's try...

I started with myself, but I was not very sure about the results...

So I used the manliest man that has ever existed.

Also had to try it with More women.

Worried about Sarah Jessica Parker.

Rudter Hauer also seems to be on the safe side..
Aaaaan, Just for laughs...

Oh, WAT?

Ok, this has been a bit difficult for the program.
Obviously, it is not foolprof, IMHO. I really don't recommend trying it if you are having concerns about facing or passability. Ir's only a demo code, and probably not the best.