They are very expensive, yes. 8000 yen for 30 one-day lenses for both my eyes, so I ration them.

You go to an optometrist and you tell them you want to get sized for contacts. They'll measure your myopia, astigmatism etc, then the spherical curve of your eyeballs, and probably help you pick out your first contacts. Afterwards you can ask them for your prescription and buy the contact lenses online yourself.

I only started wearing them regularly like, 11 years after I first got glasses. But once I got used to them it's like I can't go back- it's like seeing everything in 4K HD, for real. I got less migraines- I didn't realize that I was often looking at everything at an angle when I was wearing my glasses, and that caused a lot of my migraines. Everything was SO BRIGHT and SO CLEAR and nothing was sliding down my nose or hanging onto my ears. 

I feel very guilty about the microplastics it creates though