Symptoms that there are eye problems would include a discharge from the eye(clear or white), redness, swelling around the eye, or your chinchilla being unable to keep one of their eyes all the way open.It makes them miserable, just like it would a human, so it's important that their owner gets them to the vet pronto, if flushing the eye out with saline solution or natural tears doesn't work.If an eye ointment or drop is needed, I've found that the eye drops work better for a chin. Eye ointments are gunky, attract dirt/dust and the chin tends to try to groom the ointment away.