Your caution is well advised, but the sun doesn't instantly burn your retinas. You do get a tiny bit of time to look away before any damage is done.

I viewed the 1979 total eclipse with binoculars, and when totality ended and the diamond ring and Baily's beads started to appear, I lingered a few seconds longer than I should have, and still no harm was done. I didn't suffer any temporary or permanent vision damage, even viewing those through the binoculars.