I spend time with my 2yr old granddaughter, she’s just learning to talk and I often mumble and stumble through a conversation with her…My mouth tends to get very dry, and that doesn’t help when it comes to speech…I end up feeling tongue-tied…
I’m also a ‘specs wearer’ but mine are on all the time. Currently just a minimal prescription for distance, but also including a tint and anti glare film. Do you have vision problems linked to your specific ataxia 
Judging distances is a problem for me, a few inches out can make a big difference between escaping unscathed or getting a bruise…For some reason getting through a doorway can really be a problem…