You could engage the services of a lawyer to write a letter to the first Optometrist, telling them to get 'off the fence' and state exactly what is their concern - and if none (sounds like it) - that they remove the restriction, and also include suggested costs and reimburse you. There seems to be far too many cases like this, and also of referring to 'friends' in the industry - at a cost. Maybe there is a kickback going on, incentivising referrals? It has to stop. Also if genuine concerns, then contact the GMC (or similar) to ask for an investigation in to the original restriction.