How many “eyes” fit across the average adult’s head? Where would you place the eyes when drawing a portrait?

Five segments equal to the size of the eye would go across a person's head. One on each side of the actual eye and one in the middle. The eyes go about halfway down the head.

Example (not my drawing btw):

1. eadweard muybridge creates series photography - 1877

2. the kinetograph - 1889

3. philo farnsworth - 1929

4. kodak introduces kodachrome - 1935

5.   once upon a time in mexico was the first film to be shot digitally - 2003

i hope this ! : )