I appreciate everyone's reply and thank you. My daughter was referred by a reputable optician to another reputable and specialist optician who diagnosed her and measured here reading speed to.improve with an overlay by over 50 words a minute! I know of someone with the condition who has successfully appealed.
Anyhow, this is not the issue, to be honest. The issue is whether I can 'appeal' (or similar)or not after the event in the light of a new condition being diagnosed when we haven't included a grammar in the original selection of schools.
You could give the admissions team at KCC a ring on Monday morning and see whether you can still change your CAF preferences, but it may be too late to do that now without making your whole application 'late', if you see what I mean. An alternative would be to leave your CAF as it is, but then ask to make a late application to one or more grammar schools after National Allocation Day (I think 'reconsideration' may be a formal process peculiar to Gloucestershire?). Even if it is too late or at least not the right time to do something now, I would try to speak to someone in Admissions before they disappear for Christmas, and get official advice.