I went to an optician for a routine eye test, and they detected something severely wrong with the appearance of my retina and called an ambulance thinking I had

I went to an optician for a routine eye test, and they detected something severely wrong with the appearance of my retina and called an ambulance thinking I had a brain aneurysm. Several hours and CT scans later, I was informed my brain was fine and I just have a strange retina, and will need annual follow up. I've been sent a letter every year since, inviting me back to the hospital, and every year they tell me it's still fine. So far I've paid £25 for the eye test (which I completed at a later date!) as I do not get my eye-tests subsidied by the NHS. However my employer reimbursed me for that too...