I studied with and graduated with my herbal medicine diploma with Dorothy.
Iridology was one of our subjects and this was our text book.
Like all Dorothy's books it is deceptively simple in its delivery, however if you are qualified in the field, her writing has so many subtle and hidden messages within it that make for quite profound insights.
I've been qualified since 1998 and still refer to this book at times and have re-read it a couple of times just as a revision and to get a dose of Dorothy's formidable knowledge and intellect. Always pick up more every time I revisit it.
Dorothy has an amazing perspective on Iridology, which would be expected given her 50+ years of experience as one of the foremost Herbalists in the field.