Sometimes, not all the time, when I close my eyes to wash my hair, I do start feeling like I'm going to fall. I started to wash my hair with at least one eye open or both open. I keep a towel hanging over the shower door so that if I get soap in my eyes I can wipe it off easier.

When I rinse my hair, I close my eyes and keep one hand either on the handle on the shower door, or on the wall next to me. So far that's kept me from sliding down the drain.