I usually have to fix my boys' topknots at least a couple times a day, and I check their eyes a lot, especially Max's. We use mostly scrunchies too.
When Max was a puppy and didn't have long enough hair for a topknot, he still got hair in his eyes. I would have to cut his hair really short to prevent that. If Joni's hair grows fast, a short style may require a lot of maintenance too, possibly weekly trims, especially if you end up cutting at the corner of the eyes.
My boys' legs/paws require weekly trimming so that the hair doesn't wrap around the bottoms of their paws. The hair grows so fast.
I've found that doing 2 bands helps with the topknot. One little ponytail closer to the eyes, then gather more hair and put a second band in closer to the ears. Some dogs do okay with a little clip or barrette, but I worry that my boys would try to swallow or chew on one if they got it out of their hair.
__________________ Kristin, Max and Teddy |