I had Misty who was picked up by her head by a dog. There was no obvious damage that we could see but a few hours later we noticed that she couldn;t close one eye. After a few tests our vet realised that the dog had damaged her nerves and she may never close her outer eyelid. Hesaid there may be a possible regeneration ( not sure of term) of the nerves.
Good news.It took a little over a year before we realised that she could close her eyes properly.