On Jul 23, 7:01 am, "tim...." wrote:
"Matty F" wrote in message

I had a test today. I wish I could understand what the prescription
means, and I wish the professionals would use a standard description.

I thought that they did!

When in China I tried to take advantage of the claimed cheapness of glasses
there.

I took my prescription with me and went into the "bargain" shop.

The assistant couldn't understand my prescription and asked me to hand my
glasses to his technician to work out my script from them.

He wrote down exactly the same numbers that were on the prescription I had
presented!

The prescription doesn't say which notation is being used.
I assume that in minus-cylinder notation, the cylinder value always
has a negative sign (but nobody will actually say that), and the
value is to be subtracted from the sphere value when on the specified
axis. Or maybe when at right angles to the specified axis. Who knows?
The axis is numbered clockwise, or maybe anticlockwise depending on
the patient's point of view or the optician's point of view. None of
the websites I have seen explains EXACTLY what the rules are.

And optometrists, ophthalmologists and orthoptists tend to use
different ways of specifying the prescription. Usually. Unless they
are Australians. What a bloody mess.
I've seen all this before - professionals using jargon to confuse
their clients so they just pay up and don't dare to argue.Why do the
pros use Latin instead of Right Eye and Left Eye?