What size of Font?

Using the data collected by my colleagues and myself it has become clear that the modal font size  of text needs to be around 14-16 point if it is not going to limit most adults reading performance. This appears to be true even when the person has the best possible glasses they can get.  It appears not to be about 'focussing' in a physics  way , but  is likely a bit like making sure your shoes fit your feet . The wrong size and walking becomes slower or limited in how far you will walk. . May I suggest that many people who read fluently and succeed academically may actually those whose eyes/retinas are able to process the images from small text!  This data has been collected objectively  from a large sample.
People asre often embarrassed to use a bigger font, because the way this country links a large font to a poor reader which is then stupidly associated with low intelligence.