Thanks for the reply.
Yesterday after posting my comment the last bit of gunk came off his other eye & he now has 2 open eyes. The balls seem to be moving exactly as they should & I will now find a specialist to test his sight. Sadly I had to take him with me on my trip as Cham sitters are...
I have a Flap Necked chameleon that I found at my gate. (They are indigenous here) sadly we seldom see them any more as between the cats and the electric fences, their numbers are dwindling. On close examination I realised he couldn't see a thing. His eyes wouldn't open. A result of shedding or...