Did you know there are different kinds of refraction? The one most people think of- where a lucky tech like me gets to stand there saying "which is better, one or two?" - that's called a subjective refraction, because we rely on the opinion of the patient to determine the prescription. There are also objective refraction options, or rather, refractions that are based on the physical makeup of your eye, rather than what you think you see. Few doctors trust these objective methods implicitly because, well, it's YOUR vision, and even if the retinascope says this is what you need, you may not like it. So, often times, objectives will be used to find a starting point and then the subjective refraction will be done by the tech or doctor to finalize a prescription.
Pain is just like vision: yes, it is something that should have objective indicators which a doctor can monitor. But, there is also a hugely subjective component that can only be measured and expressed by the patient. And, just like most people find the which is better test to be stressful (because the B looks better on one, but the N is darker on two, and how am I supposed to know which one I prefer, this is beginning to feel like a life or death decision ohmygod someone please help me I'm DYING!) trying to measure your level of pain becomes one big mind fuck. "My fingers are killing me today, but they don't look swollen. And my knees won't bend, but there are no pressure systems near me, there aren't even tiny storm cells to watch. Maybe it's in my head. Maybe I'm not really sick, I'm just whiny and if I bucked up I would be fine."
That's the problem with having an invisible disease: yes it's hard to convince others that you are sick, but at one point or another you're going to end up psyching yourself out and feeling like a hypochondriac. Because, can you REALLY be sick if you don't look sick?
Yes. The answer, is yes.