She probably injured her eyes while rubbing. The concerning thing is that she is rubbing. It usually indicates some kind of parasitic infection.
How long have you had her and did you qt
her? Any other symptoms such as fast gilling, hovering in 1 spot, lethargy, etc?
Also do you have a qt
tank? I would get one ready promply and prepare to begin parasitic treatment. DO NOT treat the main tank whatever you do.
Do you see any white spots? If there are and they are of uniform size, It would be ich, but from what you explain, I believe she may have marine velvet. How is your water quality? Please give us a rundown so we can eliminate water quality issues.
Also can you post a picture of her?