I have read some accounts of comfrey being so good at knitting tissue together that it caused parts that shouldn't be together to grow together. For example, people using it as a diaper rash cream and having tissue down there fuse together, requiring surgical intervention. I don't know if this is overblown. I do know comfrey is very powerful at promoting quick tissue growth. I probably wouldn't put it in my eye or in contact with my eye lids personally. Those little bristly hairs seem like they could irritate too.
I like to always use the gentlest plant first, then if that doesn't work, move onto "stronger" plants. If it were me, I would try plantain you mentioned first, since it is so gentle, but still quite powerful in its way. I once had a nasty stye, my eye was swollen almost completely closed. I put a plantain spit poultice on it. Later that day, my eye was completely normal again. So I can certainly attest to its ability to help soothe eye conditions. Violet might also be a good option for an eye wash.
You might find this video about herbal eye washes and eye cups useful too. I believe he gives suggestions for different herbs once could use as well as measures to ensure everything is clean and safe for eyes.
“Action on behalf of life transforms. Because the relationship between self and the world is reciprocal, it is not a question of first getting enlightened or saved and then acting. As we work to heal the earth, the earth heals us.” ~ Robin Wall Kimmerer