Just a quick update for anyone who might stumble across this thread in the future. I received a letter today from the CAA which I've typed out below:
Thank you for your email regarding your intention to undergo surgery for correction of a diverging squint. I have now had the opportunity to discuss your letter with my colleague, Mr Chorley, who advises that should you elect to put yourself forward for the surgery, we would require a report from your consultant surgeon at the time of your discharge. We will then be able to advise you on the appropriate time to elapse before we can assess you for JAA Class one medical certification.
From the information you give in your letter, you do not appear to have any problems with your visual acuity and should, therefore, fulfil the standard for JAA class one medical certification from the vision point of view.
The CAA were kind enough to ring me a few weeks ago to let me know what the letter said before it went away to be typed, so I actually had the surgery done on Saturday. My eye is sore now (but straight!) and I have no double vision. The surgeon said that he is happy to write a report and is of the opinion that I am safe to drive and operate heavy machinery immediately, and will say so in his report.
Hope this is helpful,
David.