Michael Caine became a style icon in the 60s due to the outstanding suits and jackets he wore on films and in his everyday life. Yet it wasn't only the clothes that set him apart from the rest, it was his eyeglasses. Bold and black framed eyewear from Oliver Goldsmith became Michael Caine's style trademark.
When wearing/buying eyewear, one should always see if the frames' design suit your face shape well. Michael Caine was completly aware of this and hence the result in this 1966 photo.