Greetings..
The classics say: "Eye follow Hand".. "When meditating [Wuji or Zhua Zhong], focus on nose"..
"eye follows hand".. doesn't mean to look at the hand.. hand represents "doing", it means focus on your intention on what you are doing..
"Focus on nose".. where "nose" refers to "breath, not the nose literally.. focus on your nose (cross-eyed) for five minutes.. and then you'll be focusing on the headache..
The classics and the ancients used metaphor liberally.. it is that culture's way of communication.. it makes no more sense to take the ancient texts verbatim as it does to take the Bible verbatim.. short stories and metaphors elicit responses or images from common experiences that resemble experiences that the communicator wishes to convey.. Yet, if you believe that you need that level of control, the universe (Tao) will make it so.. it is much more cooperative than you know..
Be well..
TaiChiBob.. "the teacher that is not also a student is neither"