I have not ever heard of this as a manifestation of CIDP. Body stress including illness can cause hair loss, but it is more likely on both sides. I did a Google Scholar search and came up with two to three possibilities.
One thing discussed is endocrine problems–such as a high or low level of thyroid or diabetes and it can be on just one eye despite these being “systemic” conditions. A second is infection/inflammation along the eyelashes–often called blepharitis. Since the area is slightly swollen and itchy this seems more likely. Blepharitis usually looks like yellow crustiness along the edge of the eyelid by the eyelashes. It can be treated with very diluted baby shampoo applied with a Q-tip along the eyelids, very gently rubbing to get rid of the crusties. You can also use a washcloth, but the Q-tip works better. This is a relatively common infection and does not seem to bother the eye itself (no pink-eye/conjunctivitis). the third thing that stood out was an autoimmune “alopecia” or loss of hair, but I did not see this just of the eyelashes.
Another thing I have seen is if the eyes itch from allergies, people can rub them and often rub one side more than the other, so you could thing about it this is any part of it. Probably not.
It the eyelashes are getting really thin or noticably-to-others thin, you might want to go to see either your primary doctor or an ophthalmologist or a dermatologist. The google scholar search said that the name of the condition for loss of eyelashes is “madarosis”–this sounds angry, doesn’t it? Medical terms are so often strange.
Saying as a e-friend, your picture shows you to have handsome eyes, so I hope it is sorted through soon. WithHope