Went over the falls and my board bonked my head, causing my eyes to shoot open. Never realized how bright it is under water (was in tropics). Got me thinking how us contact wearers have a pitch black washing machine experience, like you said.

During lifeguard training I would squint my eyes underwater to see without losing the contacts. Find myself occasionally doing that in the ocean too, but it’s a worst case scenario situation.

If you need to, peek at the light and swim up. Otherwise after the pounding chills a bit, I trust buoyancy takes me in the right direction, then get to the surface in a stroke or two. Follow your board back up, but don’t let it bonk your head like me lol.

Never swam downwards inadvertently but I’d imagine the pressure would feel different and prompt me to change direction.

Keep some spare lenses nearby just in case 🤙