Quote:
Originally Posted by Perikles
I imagine it is simply called 'strength', a strength of 2 diopters, say. Or grade? The value is the inverse of the focal length of the lens in metres, so the higher the number, the 'stronger' are the lenses. I am just guessing at the word, though.
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Informally "strength" is the word used. I dug through the piles of paper on my desk but I can't find my latest prescription to check the wording used on that.
Hmm, over two years since I saw an optician. I should make an appointment.