Delvis, it takes time to get diagnosed but initially you would need to go to the docs. I was originally told its labyrinthitis which is a virus, but after it didn't go away, I was sent to the 'dizzy clinic' for 'balance system training'. When this didn't work (basically its making yourself dizzy and then telling yourself you aren't...) they then said it was menieres and that's the end of it!
Regarding your eyesight not being connected to your ears, I learnt that 'balance' relies on three aspects of the body, sight, muscles and ears. So if you take one away, (in my case ears) then the others have to work harder. Also it's more difficult for me to walk in the dark or over rough ground as that's over using the other balance 'organs'. It's also why, as a symptom of having menieres, I'm very tired, as my brain is having to work hard all of the time.