If you read the directions on VetRx, it does not say put it IN the eye, but in the opening at the roof of the mouth, up in the nasal cavity area. It has camphor in it, which probably would burn like fire inside the eye.
Just be aware that if she has something contagious, she may remain a carrier, meaning she will always be able to infect other birds, even if she seems to heal up. Antibiotics do nothing for a virus, as you probably know. Many old time poultry keepers never treat anything respiratory at all. Either they separate the bird and see if its immune system will take over or they immediately cull the bird to keep whatever it has from spreading. They also want birds with strong immune systems, which is another reason not to treat a bird with respiratory ailments. Everyone must make their own decisions about this, but everyone also needs to have the proper information to make those decisions--chickens do not catch head colds like humans do, no matter what the VetRx instructions tell you.
Here are the eyeworm directions from the label:
To treat, hold bird under your arm so you have both hands free. Open bird's mouth while turning its head to side and tilting down so you can see the cleft in the roof of the mouth. Dip a small cotton swab into warm VETRX. Press swab right into cleft. Do this slowly. Watch for VetRx to come from each side of bird's beak and pus coming from corner of each eye. Remove pus and rest bird for awhile. You may have to repeat treatment two or three times before you see results.