I am currently working through my coursework and on one question I have been asked: What do you understand by the term "High" power positive lenses and provide an example prescription which is suitable. State and explain two sources of evidence to support your answer.

Now I understand that, lets say a +10.00 could be defined as a high positive power, but where does the "High" start from? would it be +5.00 due to requiring BVD based on the opticians act? I am really not too sure what to write in this answer, let alone find relevant examples.

I have gone through a few books looking for information (Jalies bible and griffiths practical dispensing)

I was hoping someone here would have any more info that I may be missing or overlooking.


Thanks.