The head mounted laser I use in practice is a way to figure out the answer to these questions.
The test I do with the laser could also give a reason why you are getting headaches, since some of the more common types of headaches have a link to neck dysfunction.
This all may sound a little odd, but watch the video to see how it works and why I use it.
To watch the video, simply click on the image below.
If you have any questions, please reach out.