Why stairs outrank every other hazard
A senior dog losing her sight does not stop moving around her home — she navigates it from memory, walking routes she has used for years with growing confidence that the world is where she left it. Flat rooms forgive that confidence. Open stairs do not. The first step down is invisible to a dog who can no longer judge edges or depth, the banister side may be an open drop, and a fall for a frail, stiff dog can mean broken bones rather than a scare.
That is why the changes that matter are the ones that remove her access to unguarded stairs entirely, rather than the ones that merely make the stairs slightly easier.
Gates, fitted properly and actually used
Fit a secure gate at the top of the stairs and another at the bottom. The top gate prevents the catastrophic fall; the bottom gate stops her wandering up when nobody is watching and then facing the descent alone. Choose gates fixed firmly enough that a large, leaning dog cannot push them through, with no wide gaps she could slip or catch a leg in, and no loose pressure fit on the stair edge itself.
Then treat the gates the way you would a lock: closed every time, by everyone, including for a thirty-second trip upstairs. Vision-loss accidents in real homes rarely happen because a family had no gate — they happen at the moment someone left it open meaning to come straight back.
If there are open or floating stairs, a landing with an open railing, or a split-level drop inside the home, block those in the same spirit. A dog following the wall with her shoulder can walk straight through a railing gap at a height she cannot see.
If she must still use some stairs
Some homes have no way to feed, garden or sleep without a few steps. For any stairs she genuinely must use, make each step easier to read with what sight she has: a strip of strongly contrasting, non-slip material on the edge of every tread, consistent lighting at the top and bottom that does not dazzle, and nothing — shoes, post, laundry — ever stored on the steps or landings.
Take her up and down on a lead or a well-fitted harness, walking on her weaker side, at her pace, one step at a time, and never let her follow you up loose or rush down ahead of you for dinner. At night, when her remaining vision is at its worst and the house is dark, she should not have access to those stairs unsupervised at all — a gate or a closed door does that job while you sleep.
The rest of the house around the stairs
Keep the furniture at the foot and head of the stairs exactly where it has always been, so her memorised turning space stays true, and keep floors on her routes free of new obstacles. Pad sharp corners along the paths she walks most, and consider a low night light on the landing so any unavoidable trip is made in the best vision she has left. If she falls, seems painful afterwards, becomes reluctant to move around, or her vision seems to worsen suddenly rather than gradually, contact your vet promptly; sudden change is not ordinary ageing and deserves to be checked.
Agreeing the gate rule, the clear-stair rule and who checks them at night through KinsLe with Family Sharing means her safety does not depend on whichever person happened to use the stairs last.