Max our 13 year old male has been under the weather. Struggling to wee, but also we noticed one eye was slightly opaque. Late afternoon yesterday a white semicircle appeared at the bottom of the eye. Vets didn't have any appointments, so got in today. There is now a red halo around the iris. Vet wasn't sure, so sent pictures to a colleague. Poor chap needs an eye exam Tuesday. Need to keep an eye on his toilet habits otherwise back tomorrow.