Definately see an optician as well...

I know someone who had been taken to the doctors with headaches whith no resolution and as far as I understand it, things dragged on for a couple of months before the optician was considered.

When she went there, the optician said something like "get her into hospital for tests at once" There were a lot of worries, and tests... Things were OK though as the cause turned out to be a known possible side effect of the drug she had been prescribed by the doctor for acne...

Jon