The font size applies to capitals with a bit of space above and below.
For you, i think The important size is the x height which ignores the assender (as in a 'h, b, k') and is specified by the font designer.
I suggest looking at your fonts in the mac font book (in applications if you dont have it open) and using a font where the x, o, a, etc look bigger (taller and wider) than your current default reading font.
I have some fonts with extreemly large assenders with correspondingly small x height.
I seem to recall that keys to legibility of text include:
Use fonts with comparatively large x-heights and relatively short ascenders and descenders.
Use of a typeface that has serifs.
Line lengths that do not exceed the length of two lower case alphabets (ie a to z twice, in lower case)
Good use of leading.
Most people probably won't have hundreds of professionally designed fonts (sorry, typefaces) on their system, but will have a handful, and probably a lot of less good ones available for free from sites such as dafont.com or from software bundles or wherever.
So yes, you can run Accordance in Papyrus and Comic sans if you really want to, but take a minute to have a look at your paper Bible on the shelf and make a close study of how it was (professionally) typeset. Examine the choice of typeface, the use of leading, the width of columns, the use of hyphenation. Observe.