I think you'll find that she won't venture onto the couch, etc. as her eyesight worsens. She'll want to stay close to the ground. As another poster mentioned, she won't enjoy unfamiliar places much anymore. But she will quickly figure out getting around in the house and in her own yard (or portion of it).
You might try using a halti collar with her. Some dogs find it less stressful because the halti points their nose in the right direction and they can easily follow (rather than having to reorientate when you pull a harness or regular collar).
In unfamiliar territory, she will take mincing footsteps. There isn't a lot you can do but to stay right with her and encourage her - touching her often in unfamiliar settings and talking to her will help a lot.
And be careful when she's sleeping, just waking, or has had a seizure, etc. She is likely to be more confused during those times and might snap out of fear.
