Are you sure it is "punch" and not "puncture"?

I do not know what a lumbar punch is, so if that is the correct term, appologies, and please ignore the rest of this post.

A lumbar puncture is an extremely common, and informative, procedure in the world of neurology, where they take a sample of cerebro-spinal fluid (CSF) and test it for everything they can think of. CFS is the fluid that bathes the brain and spinal cord. If you have been referred to a neurologist in relation to the loss of sight in one eye, a lumber puncture would not be an unusual investigation. In basically gives them an idea of the physiological state of environment in which your brain and spinal cord float.

Are there any other investigations planned? Is this part of investigations related to lymphoma?

Once again, if the term actually is punch rather than puncture, please ignore this.
Best wishes
Simon