system
Given the following post, respond as if you're commenting on Reddit:
human
Does the "location" of a headache have anything to do with the cause?

I guess this is based on the premise that headaches that "feel" like they're in different parts of your head have different causes, which may well be false.

Assuming it's true, could you reason that a headache in the back of your head is related to eyestrain (occipital lobe)?  Alternately, is a headache caused by dehydration located in a different place than one caused by ice cream?

I'm guessing migraines are an exception to this.
gpt
Some conditions classically present with pain in specific paces, e.g. Subarrachnoid haemorhage classically feels like someone hit you on the back of the head with a baseball bat and that is where the pain is typically localised to, despite the bleed being spread all over the place. Others however like acute angle Glaucoma can present with pain localised around the orbital area. 

The majority of headaches however are termed tension headaches and while their aetiology is essentially unknown, they are quite benign with no underlying pathology identified. The idea that stimulating your eyes could cause pain in the corresponding brain area is flawed as the brain is incapable of feeling pain and therefore the perceived location of the pain is unlikely to have anything to do with the inputting sensory organ.