You can also find out ethnicity and even sub-ethnicity among some other things.

The Cup-Disk Ratio in a fundus scan is very notably different in people from two regions of the Indian subcontinent. And you can implement this with pre-Deep Learning Computer Vision.

I worked for a while with fundus and OCT scans of eyes and Deep Learning. The optometrists working there used to tell me this things.

Existance of the Y chromosome causes a major difference (gender, body shape, hormones etc.) so it's not surprising it causes minor differences too.

I agree, but if I were building evil robot to conquer the world, I'd probably change the height and weight for different fighting strategies and tasks, but I'd not mess with the optic system too much.