Re: Plus and minus prescriptions

"Eva via MedKB.com" <u36039@uwe> wrote in message news:866a39388c21c@xxxxxx
I read that plus prescriptions and minus prescriptions are very different
in
the way they affect people's eyesight.

For example, my husband wears a +3 full time, I wear -3. I read that +3
equates to vision without glasses of 20/100 while a -3 is like 20/300. It
sounds like a big difference, is it correct?

A +3 is farsighted and a -3 is nearsighted. The designation of 20/100,
20/300, etc is a measurement taken at 20 feet viewing distance, so a
farsighted person with +3 can see better at 20 ft than a nearsighted person
with -3. But a nearsighted person can see better up close than a farsighted
person.

Some government agencies such as your Department of Motor Vehicles does not
care how well you see at reading distance. They are interested in how well
you see at a distance (needed for driving safely). A school may have the
opposite interest, since they need to make sure a student can read.


.