Firstly, I totally agree with the previous posters.
I'm just here to add my own story since I also have a blind horse (blind from ERU - so mostly likely not genetic and 100% not caused by injury - the most likely cause in my girl's case is a virus/"worm" she got many many years ago) and I can totally relate with you.
Initially, with my girl I was very worried about working on the ground with her because she doesn't respect your space like a seeing horse would (trained seeing horse, that is). She tries to respect my space but sometimes she really gets close and I would (still do sometimes) get nervous thinking she was going to hurt me on accident.
However, I finally figured out that if I started talking to her the moment I felt nervous (and not wait until she was "too close" like I would with a normal horse - my gut wanted to wait and "correct" the behavior when it happened so I had to reprogram myself to preemptively caution) she'll generally recalculate her path so she avoids me. She may still brush me but once she knows where I am, she makes sure that any sort of touching occurs at a walk and that there's no danger to me.
My girl, at least, once I started helping her succeed, has really developed this side where she's extremely cautious when she knows there are "dangers" about. Sometimes there will be children running around her and, instead of getting nervous like I would expect, she starts really thinking hard before moving at all. I've actually seen her turn around when she's unsure and she will literally take 6 inch steps, just moving hoof widths around until she makes it as far as she wants because she's aware that smaller steps are easier to control than bigger ones.
The other things that I've found really helpful are: having little noises for everything and having my keys on a carabiner clipped to my pants whenever I'm around her so she can hear me without me talking (I'm not a huge talker when I'm alone and I use so many other noises with her that I don't want to decrease the importance of verbal info, yknow?).
As far as the noises go, some people have really elaborate systems with their blind horses. Personally, I don't. Lacey has a natural knack for elaborating on cues so our words use that skill of hers (each word is contextual).
We use "HO!!" for "DANGER, stop NOW and don't move until I say!", "hoooo" for "stop, no danger but stop", "step" for "you need to step over something tall/through something narrow+tall", "careful" for "there are deviations in the ground, place your feet carefully", "eh-eh-eh!" for "it's ok to move but you are very close to an obstacle (human/animal/stationary) so watch yourself", "excuse me!" for "I'm right here and you're in my way, move however you want but move", and finally, her favorite: "OK!" which means "every situational cue previous to this is over". "Ok" means "you're free and clear, no danger" if I've just taken her halter off but while working, "ok" just means that all previous cues are finished.
Then there's the usual "Good girl" and "back up", etc.
I've found that with her, touch is of utmost importance. She is ALWAYS touching me to gain cues about the world, especially hen she's nervous. I've found that when leading her, especially if she's nervous, holding the halter directly under her chin (ie, the way you're "never" supposed to lead a horse
) gives her a bunch more confidence. I could not understand that for quite a while but then I realized that for her, when I'm leading her with my hand down the rope, I really could have disappeared for all she knows. And, it makes perfect sense that when she's confident, who cares if "mom" is right there? But when she's nervous, she wants to get as many cues as possible and when I've been "disappeared", how is she going to get those cues?
And so, while touching a horse that's a it "hyped" seems opposite to a good idea for continuing to live, I've personally found that there's a real calming effect to a CALM touch (if it's a nervous touch, that won't help, obviously! haha)
I was still riding my girl up until she injured herself a few weeks ago (running around too much without seeing the ground! haha) and she did absolutely fine. We trail ride/rode and we would often come across obstacles we would have to cross. She never had any difficulty if I cued hr correctly. Of course, if my timing was off or if I didn't give her enough confidence, then we would have trouble. But we managed. We would often run on the trails too so it's not like we ere just walking along constantly. :)
Confidence with horses in general is a give and take bu especially with blind horses. When you're handling them, they're trusting you 100% to keep them safe, they're basically taking alll the responsibilities of the herd (watching for danger, alerting the herd to danger, guiding the herd somewhere safe, etc) on you. They know they can't protect themselves at all and you therefore ARE the protector/alerter/guider. It's a really intense role but one that's super rewarding.
I found this link to be really helpful when my girl was first diagnosed: Blind Horse Care, Training, and Riding
It has a lot of practical tips that just make life easier. :)
And figure out what works for you two. I've found that the things that work for my girl and me are often things that go exactly against common horsekeeping "say so". However, I personally feel that if you're both staying safe and it works, who cares if it's a bit unconventional? The main thing is that you both are safe and feel safe. Don't be afraid to try stuff to "find out".
Your girl is lucky to have someone that obviously cares so much about her! :)
And I'm so sorry about the loss of your husband.